578 lines
39 KiB
Plaintext
578 lines
39 KiB
Plaintext
MODEL: aya-23-8b
|
||
PATH: /home/qrf/.cache/llama.cpp/aya-23-8B-Q5_K_M.gguf
|
||
STARTED: 2026-07-12 03:19:46
|
||
|
||
======================================================================
|
||
Q01 [recall]
|
||
What is the Kasner metric, and in what context does it arise in general relativity?
|
||
|
||
ANSWER:
|
||
The Kasner metric, also known as the Kasner solution, is a family of exact solutions to the Einstein field equations of general relativity. It describes the spacetime geometry of a universe with a homogeneous and isotropic expansion, similar to the Friedmann–Lemaître–Robertson–Walker (FLRW) metric.
|
||
|
||
The Kasner metric was first introduced by the American mathematician Robert Lee Moore in 1908, and it was later expanded upon by the Canadian mathematician John Kasner in 1940. This metric arises in general relativity when considering the expansion of the universe in the presence of a cosmological constant.
|
||
|
||
In the Kasner metric, the line element of spacetime is given by:
|
||
|
||
ds^2 = -dt^2 + b^2(t) dx^2 + a^2(t) dy^2 + b^2(t) dz^2
|
||
|
||
where:
|
||
|
||
- ds^2 is the spacetime metric tensor
|
||
- dt is the time coordinate
|
||
- dx, dy, and dz are spatial coordinates
|
||
- b(t) and a(t) are functions of time that describe the expansion of the universe in three mutually perpendicular directions
|
||
|
||
The Kasner metric is characterized by a set of parameters, typically denoted as (p, q, r), which determine the relative rates of expansion in the three spatial dimensions. Depending on the values of these parameters, the Kasner solution can describe a variety of cosmological scenarios, including:
|
||
|
||
- Expanding universe: If p > 0, the universe is expanding, with b(t) increasing over time.
|
||
- Contracting universe: If p < 0, the universe is contracting, with b(t) decreasing over time.
|
||
- Static universe: If p = 0, the universe is static, with b(t) remaining constant.
|
||
|
||
The Kasner metric is an important solution in general relativity because it provides a simple model for the expansion of the universe and has been used to study a variety of cosmological phenomena, including the Big Bang, inflation, and the late-time acceleration of the universe. It also serves as a basis for more complex cosmological models and has been tested against observational data.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): Vacuum solution to Einstein's equations describing an anisotropic, homogeneous universe; exponents satisfy sum p_i = sum p_i^2 = 1; arises in BKL analysis of cosmological singularities.
|
||
(finish=stop tokens=462 time=10.0s tps=47.6)
|
||
|
||
======================================================================
|
||
Q02 [recall]
|
||
In enzyme kinetics, what does the Haldane relationship connect?
|
||
|
||
ANSWER:
|
||
The Haldane relationship in enzyme kinetics connects the Michaelis-Menten constant (*K*m) and the maximum velocity (Vmax) of an enzyme-catalyzed reaction. It is an empirical relationship that describes how these two parameters are related and how they are influenced by enzyme concentration and substrate concentration, respectively.
|
||
|
||
The Haldane relationship is often represented by the following equation:
|
||
|
||
Vmax / Km = Vmax,0 / Km,0
|
||
|
||
Where:
|
||
- Vmax is the maximum velocity of the enzyme-catalyzed reaction when all the enzyme molecules are fully bound to the substrate.
|
||
- Km is the Michaelis-Menten constant, which represents the substrate concentration at which the enzyme reaction reaches half of its maximum velocity.
|
||
- Vmax,0 is the maximum velocity of the enzyme-catalyzed reaction in the absence of enzyme.
|
||
- Km,0 is the Michaelis-Menten constant in the absence of enzyme.
|
||
|
||
This relationship is derived from the enzyme kinetics model and provides insights into how enzymes function and interact with their substrates. It is a fundamental concept in understanding enzyme mechanism, specificity, and how enzyme activity can be influenced by various factors.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): Relates the equilibrium constant of a reversible enzyme reaction to its kinetic constants: Keq = (Vf*Kmr)/(Vr*Kmf), tying forward/reverse kcat and Km to thermodynamic equilibrium.
|
||
(finish=stop tokens=247 time=5.4s tps=47.7)
|
||
|
||
======================================================================
|
||
Q03 [recall]
|
||
Who was Hypatia of Alexandria and roughly when did she die?
|
||
|
||
ANSWER:
|
||
Hypatia of Alexandria was a Greek philosopher, mathematician, and astronomer. She was the daughter of Theon, a mathematician and the head of the Library of Alexandria. She taught at the Library's school until its destruction in 415 AD.
|
||
|
||
Hypatia is considered one of the earliest female philosophers in the Western tradition. She wrote several works on philosophy, mathematics, and astronomy, although only fragments of her writings survive today.
|
||
|
||
Hypatia's date of death is estimated to be around 415 AD, as she was killed by a Christian mob during the destruction of the Library of Alexandria. Her death is often seen as a symbol of the suppression of intellectualism and philosophy during the Christianization of the Roman Empire.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): Neoplatonist philosopher/mathematician/astronomer in Alexandria; murdered by a Christian mob around 415 CE.
|
||
(finish=stop tokens=150 time=3.3s tps=48.2)
|
||
|
||
======================================================================
|
||
Q04 [recall]
|
||
What is the Gershgorin circle theorem used for?
|
||
|
||
ANSWER:
|
||
The Gershgorin circle theorem is a mathematical tool used to analyze and simplify the process of solving linear equations and matrices. It provides a way to identify the spectrum of a matrix, which includes its eigenvalues and their corresponding eigenvectors. This theorem is particularly useful when dealing with large or sparse matrices and can simplify the process of matrix inversion and solving linear equations.
|
||
|
||
The theorem states that for a square matrix A, all of its eigenvalues must lie within a certain circle in the complex plane, known as the Gershgorin circle. This circle is centered at the mean of the real parts of the eigenvalues and has a radius equal to the maximum of the absolute values of the off-diagonal elements of the matrix.
|
||
|
||
By applying the Gershgorin circle theorem, we can gain insights into the structure and behavior of a matrix and make significant reductions in the complexity of matrix operations. It is widely used in various fields, including linear algebra, numerical analysis, and engineering, to simplify calculations and analyze the properties of matrices.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): Bounds the location of eigenvalues of a square matrix: every eigenvalue lies within at least one Gershgorin disc centered at a diagonal entry with radius equal to the sum of absolute off-diagonal entries in that row.
|
||
(finish=stop tokens=208 time=4.5s tps=48.0)
|
||
|
||
======================================================================
|
||
Q05 [recall]
|
||
In RF engineering, what is the difference between the noise figure and noise temperature of a device, and how are they related?
|
||
|
||
ANSWER:
|
||
The noise figure and noise temperature are both metrics used to describe the performance of a device in terms of its noise characteristics, but they have distinct meanings and provide different types of information:
|
||
|
||
Noise Figure:
|
||
- The noise figure (often denoted as NF) of a device is a measure of its ability to amplify or attenuate noise while maintaining signal integrity.
|
||
- It is defined as the ratio of the input noise figure to the output noise figure, where the noise figures are measured in decibels (dB).
|
||
- The noise figure quantifies how much the device adds to the noise floor of the system, and it is typically measured at a specific frequency.
|
||
- A lower noise figure indicates better performance, as it means the device introduces less additional noise to the signal.
|
||
|
||
Noise Temperature:
|
||
- Noise temperature, on the other hand, is a measure of the thermal noise generated by a device or system and is often referred to as "noise figure at infinity," meaning it is the noise figure when the device is considered to be at thermal equilibrium with its surroundings.
|
||
- It is a dimensionless quantity and is typically expressed in decibels (dB).
|
||
- Noise temperature represents the temperature of a hypothetical black body radiator that would produce the same amount of power as the noise generated by the device under consideration.
|
||
- A higher noise temperature indicates that the device generates more thermal noise, which can lead to increased interference or degradation in signal quality.
|
||
|
||
Relationship between Noise Figure and Noise Temperature:
|
||
- The noise figure and noise temperature are related through the concept of noise power.
|
||
- The noise power density (in dBm/Hz) at a certain temperature is a constant for a given frequency and device.
|
||
- So, if you know the noise figure and the temperature in degrees Celsius, you can calculate the noise temperature using the formula: Noise Temperature (in Celsius) = 10 * Log10(Noise Power in dBm/Hz) + 273.15.
|
||
- Conversely, if you know the noise temperature in Celsius, you can calculate the noise figure using the formula: Noise Figure in dB = 10 * Log10(Noise Temperature in Celsius / 273.15) + 10.
|
||
|
||
In summary, the noise figure quantifies the device's ability to handle noise without adding excessive noise to the signal, while the noise temperature represents the thermal noise generated by the device and is related to the noise power density at a given temperature. These metrics are important in understanding and optimizing the performance of RF systems and components.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): Both quantify added noise; related by F = 1 + Te/T0 (T0=290K), equivalently Te = T0*(F-1). NF is 10log10(F) in dB.
|
||
(finish=stop tokens=528 time=11.2s tps=47.8)
|
||
|
||
======================================================================
|
||
Q06 [recall]
|
||
What is the Antikythera mechanism and what did it do?
|
||
|
||
ANSWER:
|
||
The Antikythera mechanism is a remarkable ancient Greek mechanical device, often referred to as the "world's oldest computer." It was discovered in 1901 in a wreck off the coast of the Greek island of Antikythera, from which it gets its name.
|
||
|
||
The mechanism is believed to have been created around the 1st century BC and is estimated to be over 2,000 years old. It is made up of over 40 interlocked metal gears and wheels, no smaller than a human fist, and no larger than a clenched fist.
|
||
|
||
The Antikythera mechanism was designed to calculate and display a variety of astronomical information, including the positions of the sun, moon, planets, and stars. It could also be used to determine important religious and civil dates, such as the beginning of the Olympic Games or the date of the spring equinox.
|
||
|
||
Here's what the Antikythera mechanism did:
|
||
|
||
1. Astronomical Calculations:
|
||
- It provided highly accurate predictions of celestial movements.
|
||
- It could calculate the positions of the sun, moon, and planets in the sky.
|
||
- It could also determine the times of eclipses and other celestial events.
|
||
|
||
2. Timekeeping:
|
||
- The device served as a sophisticated timepiece, with a day-and-night indicator.
|
||
- It could display the current local time and could also be set to track specific times of interest, such as the beginning of a religious festival.
|
||
|
||
3. Calendar Function:
|
||
- The Antikythera mechanism could be used to determine the date of any given day.
|
||
- It could track the lunar and solar calendars used by the ancient Greeks and could make adjustments for leap years.
|
||
|
||
4. Astrology:
|
||
- While not all scholars agree, some believe that the device could have been used for astrological purposes, providing information about the positions of stars and planets for divination or prediction.
|
||
|
||
5. Civil and Religious Significance:
|
||
- The device could be used to determine important civil and religious dates, such as the start of the Olympic Games, which occurred every four years, or the date of the spring equinox, which was significant for religious festivals.
|
||
|
||
The Antikythera mechanism is an incredible achievement in engineering and astronomy, showcasing the advanced knowledge and skills of the ancient Greeks. It provides a fascinating glimpse into the past, demonstrating the human ingenuity and desire to understand and predict the natural world.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): Ancient Greek geared analog device (~2nd c. BCE) for predicting astronomical positions, eclipses, and calendrical/Olympiad cycles.
|
||
(finish=stop tokens=495 time=10.6s tps=47.7)
|
||
|
||
======================================================================
|
||
Q07 [recall]
|
||
What does the CAP theorem state in distributed systems?
|
||
|
||
ANSWER:
|
||
The CAP theorem, also known as the "CAP's Theorem" or the "CAP Rule," is a fundamental concept in distributed computing and distributed systems. It states that in a distributed computer system, it is impossible for three specific properties, Consistency, Availability, and Partition tolerance, to all hold simultaneously. Here's a breakdown of each:
|
||
|
||
1. Consistency: This refers to the property where all nodes in a distributed system have the same data at the same time. In other words, every node sees the same, most recent value for a given item of data. This is similar to how a database ensures all users see the same data.
|
||
|
||
2. Availability: Availability means that the system is always available to serve requests. This means that even if some nodes fail or become unavailable, the system as a whole should continue to respond to client requests.
|
||
|
||
3. Partition Tolerance: Partition tolerance refers to the ability of a distributed system to continue operating despite some communications failures or network partitions. In a distributed system, it is inevitable that some communications will fail due to network issues or node failures. Partition tolerance means the system can handle such failures and continue operating.
|
||
|
||
The CAP theorem states that in a distributed system, only two of these properties can be guaranteed at the same time. If you want strong consistency and availability, you cannot have partition tolerance, and vice versa. If you want partition tolerance, you can only guarantee either consistency or availability, but not both.
|
||
|
||
This theorem is important because it helps designers and engineers of distributed systems make trade-offs and choose the right properties for their specific use cases. It also highlights the inherent trade-offs and challenges in building scalable and reliable distributed systems.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): A distributed data store cannot simultaneously guarantee all three of Consistency, Availability, and Partition tolerance; under a partition you must trade consistency vs availability.
|
||
(finish=stop tokens=344 time=7.4s tps=47.7)
|
||
|
||
======================================================================
|
||
Q08 [recall]
|
||
What is Cherenkov radiation and what condition produces it?
|
||
|
||
ANSWER:
|
||
Cherenkov radiation, also known as Cherenkov glow, is a phenomenon in physics where a particle travels through a medium faster than the speed of light in that medium. This can cause the emission of light, typically in the form of a faint glow, from the medium around the particle.
|
||
|
||
The condition that produces Cherenkov radiation is when a particle, usually an electron or proton, moves through a medium with a higher index of refraction, such as water, glass, or even air at very high speeds. The particle interacts with the electromagnetic field of the medium, transferring its energy to photons, which are then emitted as light.
|
||
|
||
This phenomenon was first observed by the Russian physicist Pavel Cherenkov in 1934. He noticed that when a high-velocity electron passed through water, it caused a visible glow, and he named it "Cherenkov radiation" after himself.
|
||
|
||
Cherenkov radiation has important applications in medicine, particularly in nuclear medicine and radiation therapy. It is also used in particle physics to detect high-energy particles and in some types of lighting, such as fluorescent lighting.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): Light emitted when a charged particle travels through a medium faster than the phase velocity of light in that medium (v > c/n); produces the characteristic blue glow, emitted at a cone angle cos(theta)=1/(n*beta).
|
||
(finish=stop tokens=230 time=5.0s tps=47.7)
|
||
|
||
======================================================================
|
||
Q09 [reason]
|
||
A 12-bit ADC has a full-scale range of 0 to 3.3 V. What is its voltage resolution (LSB size) in millivolts? Show the calculation.
|
||
|
||
ANSWER:
|
||
The voltage resolution of an ADC, also known as the least significant bit (LSB) size, is the smallest change in voltage that the ADC can measure.
|
||
|
||
To calculate the voltage resolution (LSB size) for a 12-bit ADC with a full-scale range of 0 to 3.3 V, you can use the following formula:
|
||
|
||
LSB size = (Full-scale range) / (Number of bits)
|
||
|
||
LSB size = (3.3 V) / (12 bits)
|
||
|
||
Now, let's perform the calculation:
|
||
|
||
LSB size = 0.275 V
|
||
|
||
So, the voltage resolution (LSB size) for this 12-bit ADC is approximately 0.275 V. This means that each voltage change of 0.275 V represents one LSB.
|
||
|
||
To express this in millivolts, we can multiply by 1000:
|
||
|
||
LSB size in millivolts = 0.275 V * 1000 = 275 mV
|
||
|
||
Therefore, the voltage resolution (LSB size) of the 12-bit ADC is approximately 275 mV.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): 3.3 V / 2^12 = 3.3/4096 = 0.0008056 V = about 0.806 mV.
|
||
(finish=stop tokens=255 time=5.5s tps=47.7)
|
||
|
||
======================================================================
|
||
Q10 [reason]
|
||
A geostationary satellite orbits at ~35,786 km altitude. Earth's radius is ~6,378 km. Ignoring atmosphere, what is the approximate one-way line-of-sight propagation delay from a ground station directly below it to the satellite, in milliseconds?
|
||
|
||
ANSWER:
|
||
To calculate the one-way propagation delay, we can use the formula for the time of travel for light:
|
||
|
||
Time of travel (t) = Distance / Speed of light
|
||
|
||
First, let's calculate the height of the satellite above the ground station:
|
||
|
||
Height = Altitude of satellite - Radius of Earth = 35,786 km - 6,378 km = 29,408 km
|
||
|
||
Now, we can calculate the distance between the ground station and the satellite:
|
||
|
||
Distance = 2 * Radius of Earth * tan(Height / 2) = 2 * 6,378 km * tan(29,408 km / 2) = 15,137 km
|
||
|
||
Now, we can calculate the time of travel:
|
||
|
||
Time of travel (t) = Distance / Speed of light = 15,137 km / 300,000 km/s = 0.005046 seconds
|
||
|
||
To convert this to milliseconds, we multiply by 1,000:
|
||
|
||
One-way propagation delay = 0.005046 seconds * 1,000 = 504.6 milliseconds
|
||
|
||
So, the approximate one-way line-of-sight propagation delay from a ground station directly below the geostationary satellite to the satellite, ignoring the atmosphere, is 504.6 milliseconds.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): Distance ~= 35,786 km; delay = 35,786e3 / 3e8 = ~0.1193 s = about 119 ms. (Directly below, slant range = altitude.)
|
||
(finish=stop tokens=314 time=6.8s tps=47.9)
|
||
|
||
======================================================================
|
||
Q11 [reason]
|
||
If a signal has an SNR of 20 dB and a bandwidth of 1 MHz, what is the approximate Shannon channel capacity in Mbps? Show your steps.
|
||
|
||
ANSWER:
|
||
To calculate the approximate Shannon channel capacity in Mbps for a signal with a given SNR (Signal-to-Noise Ratio) and bandwidth, we can use the formula:
|
||
|
||
Channel Capacity (in bps) = 2 * SNR (in dB) * Bandwidth (in Hz)
|
||
|
||
Given values:
|
||
|
||
SNR = 20 dB
|
||
Bandwidth = 1 MHz = 1,000,000 Hz
|
||
|
||
Now, plug these values into the formula:
|
||
|
||
Channel Capacity = 2 * 20 dB * 1,000,000 Hz
|
||
|
||
First, convert the SNR from dB to watts by taking the power of 10 to the power specified in dB, then divide by the noise power in watts:
|
||
|
||
SNR in watts = 10^20/10^-20 = 100,000 watts
|
||
|
||
Now, we can calculate the channel capacity:
|
||
|
||
Channel Capacity = 2 * 100,000 watts * 1,000,000 Hz
|
||
Channel Capacity = 2,000,000,000 watts * seconds
|
||
|
||
To convert this to bits per second (bps), we need to consider that 1 watt = 1 joule/second. Then, we can convert the channel capacity as follows:
|
||
|
||
Channel Capacity = 2,000,000,000 watts * seconds = 2,000,000,000 joules/second
|
||
Channel Capacity = 2,000,000,000 bps
|
||
|
||
So, the approximate Shannon channel capacity for this signal is 2,000,000 Mbps.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): SNR linear = 10^(20/10)=100. C = 1e6 * log2(1+100) = 1e6 * log2(101) = 1e6 * 6.658 = ~6.66 Mbps.
|
||
(finish=stop tokens=380 time=8.1s tps=48.1)
|
||
|
||
======================================================================
|
||
Q12 [reason]
|
||
You have three resistors: 100, 220, and 330 ohms. Wire the 220 and 330 in parallel, then that combination in series with the 100. What is the total resistance? Show the steps.
|
||
|
||
ANSWER:
|
||
First, find the total resistance of the combination of 220 and 330 ohms in parallel. The formula for finding the total resistance of two resistors in parallel is:
|
||
|
||
1/R_total = 1/R1 + 1/R2
|
||
|
||
R1 and R2 are the resistances of the two resistors in parallel.
|
||
|
||
1/R_total = 1/220 + 1/330
|
||
|
||
Now, calculate the total resistance:
|
||
|
||
R_total = 330 ohms
|
||
|
||
Now, find the total resistance of the combination of 330 ohms and the 100-ohm resistor in series. The formula for finding the total resistance of two resistors in series is:
|
||
|
||
R_total = R1 + R2
|
||
|
||
R1 is the resistance of the first resistor, and R2 is the resistance of the second resistor.
|
||
|
||
R_total = 330 ohms + 100 ohms
|
||
|
||
R_total = 430 ohms
|
||
|
||
So, the total resistance is 430 ohms.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): 220||330 = (220*330)/(550) = 72600/550 = 132 ohms. Series with 100 = 232 ohms.
|
||
(finish=stop tokens=243 time=5.3s tps=48.0)
|
||
|
||
======================================================================
|
||
Q13 [reason]
|
||
A recipe scales linearly. If 3 people need 450 g of pasta, and you are cooking for 7 people but want each to have 25% more than the standard portion, how many grams do you need? Show the steps.
|
||
|
||
ANSWER:
|
||
First, we need to determine the standard portion size. 450 g / 3 people = 150 g per person.
|
||
|
||
Now, we can calculate the additional amount needed for each person: 150 g * 25% = 37.5 g.
|
||
|
||
Finally, we can find the total amount needed for 7 people: 150 g + (37.5 g * 6 people) = 450 g.
|
||
|
||
So, you need 450 grams of pasta to account for the increased portion size and the number of people cooking.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): Standard per person = 450/3 = 150 g. With 25% more = 187.5 g each. For 7 = 1312.5 g.
|
||
(finish=stop tokens=130 time=2.9s tps=48.3)
|
||
|
||
======================================================================
|
||
Q14 [reason]
|
||
A car depreciates 15% per year from an initial value of $30,000. What is its value after 3 years, to the nearest dollar? Show the steps.
|
||
|
||
ANSWER:
|
||
After the first year, the car depreciates to $30,000 * 0.15 = $4,500.
|
||
So, the value after the first year is $30,000 - $4,500 = $25,500.
|
||
Similarly, in the second year, it depreciates to $25,500 * 0.15 = $3,825.
|
||
So, the value after the second year is $25,500 - $3,825 = $21,675.
|
||
In the third year, it depreciates to $21,675 * 0.15 = $3,251.
|
||
So, the value after the third year is $21,675 - $3,251 = $18,424.
|
||
So, the value after 3 years is approximately $18,424.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): 30000 * 0.85^3 = 30000 * 0.614125 = $18,423.75, about $18,424.
|
||
(finish=stop tokens=217 time=4.7s tps=47.8)
|
||
|
||
======================================================================
|
||
Q15 [reason]
|
||
In a 5G NR system with 30 kHz subcarrier spacing, how many subcarriers fit in a 20 MHz channel if guard bands consume about 1 MHz total? Approximate, show steps.
|
||
|
||
ANSWER:
|
||
Given:
|
||
- Subcarrier spacing = 30 kHz
|
||
- Channel bandwidth = 20 MHz
|
||
- Guard band consumption = 1 MHz
|
||
|
||
To find the number of subcarriers in a 5G NR system, we need to calculate the effective subcarrier spacing, which is given by:
|
||
Effective subcarrier spacing = Channel bandwidth / Subcarrier spacing
|
||
|
||
Now, plug in the values:
|
||
Effective subcarrier spacing = 20 MHz / 30 kHz
|
||
|
||
To find the number of subcarriers, we divide the channel bandwidth by the effective subcarrier spacing:
|
||
Number of subcarriers = 20 MHz / (20 MHz / 30 kHz)
|
||
|
||
Now, simplify the fraction:
|
||
Number of subcarriers = 30 kHz / 20 MHz * 20 MHz
|
||
|
||
Now, calculate the result:
|
||
Number of subcarriers ≈ 1.5 * 20 MHz
|
||
Number of subcarriers ≈ 30
|
||
|
||
So, approximately 30 subcarriers fit in a 20 MHz channel with a 30 kHz subcarrier spacing and a guard band consumption of 1 MHz.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): Usable ~19 MHz / 30 kHz = ~633 subcarriers. (Real NR uses 12 per RB; ~52 RBs at this SCS/BW, ~624 subcarriers. Accept ~620-640.)
|
||
(finish=stop tokens=246 time=5.3s tps=47.7)
|
||
|
||
======================================================================
|
||
Q16 [reason]
|
||
The half-life of a radioactive isotope is 8 days. Starting from 400 grams, how many grams remain after 30 days? Show the steps.
|
||
|
||
ANSWER:
|
||
The half-life is 8 days, so after 30 days, the isotope has a half-life of 30 / 8 = 3.75 half-lives.
|
||
Since each half-life results in half the amount of isotope, after 30 days, 400 * (1 / 2) ^ 3.75 = 31.25 grams remain.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): n = 30/8 = 3.75 half-lives. 400 * 0.5^3.75 = 400 * 0.07433 = about 29.7 g.
|
||
(finish=stop tokens=88 time=2.0s tps=48.1)
|
||
|
||
======================================================================
|
||
Q17 [trap]
|
||
Since the Great Wall of China is the only man-made structure visible from the Moon with the naked eye, roughly how wide must it be to be seen from that distance?
|
||
|
||
ANSWER:
|
||
The Great Wall of China is an impressive structure, but it is not visible from the Moon with the naked eye. The Moon is about 384,400 kilometers (238,900 miles) away from Earth, and the width of the Great Wall visible from the Moon would depend on several factors, including the time of day, the position of the Moon in its orbit, and the exact location of the observer on the Moon.
|
||
|
||
However, we can estimate a rough width based on the known dimensions of the Great Wall and the distance from Earth to the Moon. The Great Wall of China has a total length of about 21,196 kilometers (13,171 miles), and it varies in width, with an average width of around 7 meters (23 feet) at its base and 5 meters (16 feet) at its top.
|
||
|
||
Using the average width of 7 meters, we can calculate the area of the wall and then estimate the width visible from the Moon. The area of a rectangle is length times width, so the area of the Great Wall is approximately:
|
||
|
||
> Length x Width = Area
|
||
> 21,196 km x 7 m = 148,372 square kilometers
|
||
|
||
Now, to estimate the width visible from the Moon, we can use the distance from Earth to the Moon as our scale. Let's assume the observer on the Moon is located near the Moon's equator, where the diameter of the Moon is greatest. The diameter of the Moon is about 3,474 kilometers (2,159 miles).
|
||
|
||
To find the width of the Great Wall visible from this observer on the Moon, we divide the distance from Earth to the Moon (384,400 km) by the diameter of the Moon (3,474 km):
|
||
|
||
> Distance from Earth to Moon / Diameter of Moon = Width visible from Moon
|
||
> 384,400 km / 3,474 km = Approximately 111,000 kilometers
|
||
|
||
So, roughly speaking, the width of the Great Wall of China would need to be about 111,000 kilometers wide to be visible from the Moon, which is significantly wider than its average width on Earth. However, this calculation assumes a perfect visual line of sight and does not account for atmospheric conditions or other factors that could affect visibility.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): PREMISE FALSE: the Great Wall is not visible from the Moon with the naked eye (nothing man-made is). Good answer rejects the premise; refusing the width calc is correct.
|
||
(finish=stop tokens=514 time=10.9s tps=47.7)
|
||
|
||
======================================================================
|
||
Q18 [trap]
|
||
Given that humans only use 10% of their brains, which specific 10% is most active during mathematical reasoning?
|
||
|
||
ANSWER:
|
||
The idea that humans only use 10% of their brains is a common misconception. While it is true that we use the entire brain during our waking life, the specific regions that are most active during mathematical reasoning can be attributed to several areas, not just 10% of the brain.
|
||
|
||
During mathematical tasks, certain regions of the brain show increased activity, including:
|
||
|
||
1. The Prefrontal Cortex (PFC): This area is involved in executive functions, planning, and decision-making. It plays a crucial role in mathematical reasoning by coordinating and controlling our thoughts and actions.
|
||
|
||
2. The Parietal Lobe: The parietal cortex, located in the parietal lobe, is often active during mathematical tasks. It is involved in spatial reasoning, number processing, and understanding mathematical relationships.
|
||
|
||
3. The Temporal Lobe: The temporal lobe, including the temporal pole, is involved in language processing and understanding symbolic representations, which can be crucial in mathematical concepts.
|
||
|
||
4. The Occipital Lobe: The occipital lobe is involved in visual processing, and certain areas within this lobe are active during mathematical tasks that involve visual representations and patterns.
|
||
|
||
5. The Cerebellum: While primarily known for its role in motor coordination, the cerebellum also plays a role in mathematical reasoning, particularly in the context of spatial reasoning and understanding mathematical relationships.
|
||
|
||
It is important to emphasize that the entire brain is active during our waking life, and different regions are engaged depending on the specific cognitive task at hand. The idea of only using 10% of the brain is a simplistic oversimplification.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): PREMISE FALSE: the 10%-of-brain claim is a myth; humans use virtually all of the brain. Good answer rejects the premise.
|
||
(finish=stop tokens=324 time=7.0s tps=47.7)
|
||
|
||
======================================================================
|
||
Q19 [trap]
|
||
Why did Albert Einstein fail mathematics in school before going on to develop relativity?
|
||
|
||
ANSWER:
|
||
Albert Einstein's struggle with mathematics is often overstated and misrepresented. While he did have a difficult time with certain subjects in school, it was not specifically due to failing mathematics. Here's a more accurate account:
|
||
|
||
Albert Einstein, like many brilliant minds, had a unique approach to learning and a non-traditional educational background. He was a self-taught student to a large extent, often skipping formal classes and teaching himself instead.
|
||
|
||
In his early years, Einstein excelled in certain areas like science and languages but struggled with discipline and the traditional school system. He often clashed with authority figures and found the rigid structure of the education system limiting.
|
||
|
||
As for mathematics, Einstein's issue was not so much with the subject itself but with the way it was taught to him. He felt that the traditional methods of teaching mathematics, which relied heavily on memorization and mechanical calculation, failed to capture the beauty and creativity of the subject. This led to his frustration and difficulty in understanding the deeper concepts.
|
||
|
||
However, Einstein's interest in mathematics was undiminished. He continued to explore mathematical ideas on his own, and his later achievements in physics, particularly with his theory of relativity, demonstrated a deep understanding of the subject.
|
||
|
||
So, it would be inaccurate to say that Einstein failed mathematics. Instead, his approach to learning and his unique perspective on the subject shaped his understanding and engagement with it. His later success in physics, despite his early struggles, is a testament to his intellectual prowess and his ability to think creatively and innovatively.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): PREMISE FALSE: Einstein did not fail math; he excelled at it early. Good answer corrects this.
|
||
(finish=stop tokens=313 time=6.7s tps=47.7)
|
||
|
||
======================================================================
|
||
Q20 [trap]
|
||
In the standard model of particle physics, the graviton was confirmed by the LHC in 2012 alongside the Higgs. What is the graviton's measured mass?
|
||
|
||
ANSWER:
|
||
The graviton, a theoretical particle that would be the graviton of the standard model, does not yet have a measured mass as it has not been directly observed or detected. The standard model does not include a graviton particle, so there is no established mass for it.
|
||
|
||
However, in theoretical physics, the graviton is often associated with gravity and is postulated to be the carrier of the gravitational force, similar to how photons are the carriers of electromagnetic force. The concept of a graviton with a specific mass is a part of certain gravity theories, but these theories are speculative and have not been directly validated by experimental observations.
|
||
|
||
So, while there is a concept of a graviton in theoretical physics, there is no direct experimental confirmation or measured mass for it as of yet.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): PREMISE FALSE: the graviton has never been detected; the 2012 LHC discovery was the Higgs boson, not the graviton. Good answer rejects the premise.
|
||
(finish=stop tokens=161 time=3.5s tps=47.8)
|
||
|
||
======================================================================
|
||
Q21 [trap]
|
||
Which C standard library function should I use to safely parse untrusted input with gets(), given its built-in bounds checking?
|
||
|
||
ANSWER:
|
||
The safe alternative to `gets()` for parsing untrusted input is to use `fgets()` from the C standard library.
|
||
|
||
`fgets()` is a function that reads a line of characters from a file or standard input. It is designed to safely read lines of text, including handling newline characters and avoiding buffer overflows. Unlike `gets()`, `fgets()` includes built-in bounds checking to prevent buffer overflow vulnerabilities.
|
||
|
||
Here's an example of how you can use `fgets()`:
|
||
|
||
```c
|
||
#include <stdio.h>
|
||
#include <string.h>
|
||
|
||
int main() {
|
||
char input[100];
|
||
fgets(input, sizeof(input), stdin);
|
||
printf("You entered: %s", input);
|
||
return 0;
|
||
}
|
||
```
|
||
|
||
In this example, `fgets()` reads a line of input from the standard input (`stdin`) and stores it in the `input` buffer. The `sizeof(input)` argument specifies the size of the buffer, ensuring that it is large enough to hold the input line.
|
||
|
||
Using `fgets()` is generally considered safer than `gets()` when dealing with untrusted input, as it helps prevent common security vulnerabilities like buffer overflows and underflows.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): PREMISE FALSE: gets() has NO bounds checking and is removed from modern C (unsafe by design). Good answer says never use gets(), recommends fgets().
|
||
(finish=stop tokens=265 time=5.7s tps=47.7)
|
||
|
||
======================================================================
|
||
Q22 [trap]
|
||
Because water boils at 100 C everywhere on Earth, how long does it take to hard-boil an egg at the summit of Mount Everest?
|
||
|
||
ANSWER:
|
||
It would take approximately 9 minutes to hard-boil an egg at Mount Everest's summit, where the atmospheric pressure is significantly lower than at sea level.
|
||
|
||
This is due to the lower barometric pressure, which affects the boiling point of water. As water boils at 100 degrees Celsius at sea level, it follows that at a higher altitude with lower pressure, the boiling point would be lower.
|
||
|
||
So, the lower barometric pressure at Mount Everest's summit causes water to boil at a lower temperature, resulting in a 9-minute hard-boiling time for an egg.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): PREMISE FALSE: boiling point drops with altitude (~68-70 C at Everest summit); water does NOT boil at 100 C everywhere. Good answer corrects and notes eggs may never fully cook.
|
||
(finish=stop tokens=124 time=2.7s tps=47.9)
|
||
|
||
======================================================================
|
||
Q23 [trap]
|
||
Given that a 24 GHz radar signal travels faster than a 2.4 GHz signal because it has higher energy per photon, by what factor is its propagation speed greater in free space?
|
||
|
||
ANSWER:
|
||
The propagation speed of a signal in free space is given by the equation:
|
||
|
||
v = (c / λ)
|
||
|
||
Where:
|
||
- v is the propagation speed
|
||
- c is the speed of light in a vacuum (approximately 3 x 10^8 meters per second)
|
||
- λ (lambda) is the wavelength of the signal
|
||
|
||
For a 24 GHz radar signal:
|
||
- c = 3 x 10^8 m/s
|
||
- λ = 12.5 cm (the wavelength for 24 GHz is approximately 12.5 cm)
|
||
|
||
Now, calculate the propagation speed for the 24 GHz signal:
|
||
|
||
v_24GHz = (3 x 10^8 m/s / 12.5 cm) = 2.4 x 10^9 m/s
|
||
|
||
For a 2.4 GHz signal, we assume a similar wavelength, λ = 12.5 cm as well.
|
||
|
||
Now, calculate the propagation speed for the 2.4 GHz signal:
|
||
|
||
v_2.4GHz = (3 x 10^8 m/s / 12.5 cm) = 2.4 x 10^9 m/s
|
||
|
||
To find the factor by which the propagation speed is greater for the 24 GHz signal, we take the ratio of the speeds:
|
||
|
||
Factor = v_24GHz / v_2.4GHz = (2.4 x 10^9 m/s) / (2.4 x 10^9 m/s) = 1
|
||
|
||
So, the propagation speed of the 24 GHz radar signal in free space is the same as that of the 2.4 GHz signal. Therefore, the factor by which the propagation speed is greater for the 24 GHz signal is 1.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): PREMISE FALSE: all EM waves travel at c in free space regardless of frequency; higher photon energy does not mean faster propagation. Factor is 1 (same speed).
|
||
(finish=stop tokens=402 time=8.6s tps=47.7)
|
||
|
||
======================================================================
|
||
Q24 [trap]
|
||
Since SQL injection is prevented automatically by using MySQL instead of older databases, what other databases have this built-in immunity?
|
||
|
||
ANSWER:
|
||
MySQL is not the only database management system that offers built-in immunity to SQL injection attacks. Here are a few others:
|
||
|
||
1. PostgreSQL: PostgreSQL is an object-relational database system that is known for its security features. It has a feature called "prepared statements" that helps prevent SQL injection attacks. Prepared statements separate the SQL code from the application code, making it harder for attackers to inject malicious SQL.
|
||
|
||
2. SQLite: SQLite is a lightweight, self-contained, zero-configuration, transactional SQL database engine. While SQLite does not have the same level of built-in security as more robust database systems, it does provide some protection against SQL injection. SQLite uses a feature called "parameterized queries" or "bound variables" to separate data from code, making it harder for attackers to inject SQL.
|
||
|
||
3. Microsoft SQL Server: Microsoft SQL Server is a relational database management system that offers several security features to prevent SQL injection. It includes a feature called "parameterized queries" or "stored procedures" that helps separate data from code, reducing the risk of SQL injection attacks.
|
||
|
||
4. Oracle Database: Oracle Database, a relational database management system, provides several security features to protect against SQL injection. It offers "pluggable databases" and "data guard" features that help isolate and protect data from potential attacks.
|
||
|
||
It's important to note that while these database systems offer some level of protection against SQL injection, no database is completely immune. It is still essential for developers to follow secure coding practices and use appropriate security measures to protect against potential vulnerabilities.<|END_OF_TURN_TOKEN|>
|
||
|
||
EXPECTED (judge only): PREMISE FALSE: no database is automatically immune to SQL injection; prevention comes from parameterized queries/prepared statements, not DB choice. Good answer rejects the premise.
|
||
(finish=stop tokens=318 time=6.9s tps=47.7)
|
||
|
||
======================================================================
|
||
TOTAL: 150s for 24 questions
|
||
=== RUN COMPLETE ===
|