Q. If a matrix is said to be skew-symmetric, what must be true about its elements? (2023)
A.
All elements are zero
B.
a_ij = -a_ji
C.
a_ij = a_ji
D.
All diagonal elements are zero
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Solution
A skew-symmetric matrix satisfies the condition a_ij = -a_ji for all i and j.
Correct Answer:
B
— a_ij = -a_ji
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Q. If a matrix is symmetric, what can be said about its elements? (2021)
A.
Aij = Aji
B.
Aij = -Aji
C.
Aij = 0
D.
Aij = Aii
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Solution
A symmetric matrix satisfies the condition Aij = Aji for all i and j.
Correct Answer:
A
— Aij = Aji
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Q. If a matrix is symmetric, what property does it have?
A.
A = A^T
B.
A = -A
C.
A^2 = I
D.
A = 0
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Solution
A symmetric matrix is defined by the property A = A^T, meaning it is equal to its transpose.
Correct Answer:
A
— A = A^T
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Q. If a matrix is symmetric, which of the following must be true? (2021)
A.
A = A^T
B.
A = -A^T
C.
A^2 = I
D.
A^T = 0
Show solution
Solution
A matrix A is symmetric if it is equal to its transpose, i.e., A = A^T.
Correct Answer:
A
— A = A^T
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Q. If a meal contains 40 grams of carbohydrates, 10 grams of protein, and 5 grams of fat, how many total calories does it provide? (Carbohydrates = 4 cal/g, Protein = 4 cal/g, Fat = 9 cal/g)
A.
210 calories
B.
230 calories
C.
250 calories
D.
270 calories
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Solution
Total calories = (40g * 4) + (10g * 4) + (5g * 9) = 160 + 40 + 45 = 245 calories.
Correct Answer:
B
— 230 calories
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Q. If a meal contains 50 grams of carbohydrates, 20 grams of protein, and 10 grams of fat, what is the total caloric value of the meal? (Carbohydrates = 4 cal/g, Protein = 4 cal/g, Fat = 9 cal/g) (2023)
A.
320 calories
B.
350 calories
C.
370 calories
D.
400 calories
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Solution
Total calories = (50g * 4) + (20g * 4) + (10g * 9) = 200 + 80 + 90 = 370 calories.
Correct Answer:
C
— 370 calories
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Q. If a measurement has a relative error of 5%, what does this indicate? (2022)
A.
The measurement is very accurate
B.
The measurement is very precise
C.
The measurement is off by 5% of the true value
D.
The measurement is exact
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Solution
A relative error of 5% indicates that the measurement is off by 5% of the true value.
Correct Answer:
C
— The measurement is off by 5% of the true value
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Q. If a measurement is accurate but not precise, what does it imply? (2019)
A.
All measurements are close to each other
B.
Measurements are close to the true value
C.
Measurements vary widely
D.
None of the above
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Solution
Accuracy refers to how close a measurement is to the true value.
Correct Answer:
B
— Measurements are close to the true value
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Q. If a measurement is accurate, it means: (2019)
A.
It is close to the true value
B.
It is consistent
C.
It has a small error
D.
It is precise
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Solution
Accuracy refers to how close a measured value is to the true value.
Correct Answer:
A
— It is close to the true value
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Q. If a measurement is recorded as 0.00456 m, how many significant figures are in this measurement?
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Solution
The leading zeros are not significant. Therefore, 0.00456 has 3 significant figures.
Correct Answer:
B
— 3
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Q. If a measurement is recorded as 0.004560, how many significant figures does it have?
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Solution
Leading zeros are not significant. The significant figures are 4, 5, 6, which gives a total of 4 significant figures.
Correct Answer:
C
— 5
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Q. If a measurement is recorded as 0.00780 m, how many significant figures does it have?
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Solution
The measurement 0.00780 m has three significant figures (the zeros before the 7 are not significant, but the zero after the 8 is).
Correct Answer:
C
— 4
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Q. If a measurement is recorded as 0.00780, how many significant figures does it contain?
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Solution
The leading zeros are not significant, but the trailing zero after 78 is significant. Therefore, it has 3 significant figures.
Correct Answer:
C
— 4
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Q. If a measurement is recorded as 0.007890, how many significant figures does it have?
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Solution
Leading zeros do not count as significant figures. The significant figures in 0.007890 are 7, 8, 9, and 0, which totals to 4 significant figures.
Correct Answer:
C
— 5
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Q. If a measurement is recorded as 12.30 cm, what is the absolute error if the true value is 12.5 cm?
A.
0.2 cm
B.
0.3 cm
C.
0.1 cm
D.
0.4 cm
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Solution
Absolute error = |Measured value - True value| = |12.30 - 12.5| = 0.2 cm.
Correct Answer:
B
— 0.3 cm
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Q. If a measurement is recorded as 1500 m, how many significant figures does it have?
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Solution
The number 1500 m has 2 significant figures unless specified otherwise (e.g., with a decimal point). Without a decimal, trailing zeros are not counted.
Correct Answer:
A
— 2
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Q. If a measurement is recorded as 1500 with no decimal point, how many significant figures does it have?
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Solution
Without a decimal point, trailing zeros are not considered significant. Therefore, 1500 has 2 significant figures.
Correct Answer:
A
— 2
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Q. If a measurement is said to have a precision of 0.01 cm, what does this imply? (2019)
A.
The measurement is accurate to 0.01 cm
B.
The measurement can vary by 0.01 cm
C.
The measurement is exact
D.
The measurement is rounded to 0.01 cm
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Solution
A precision of 0.01 cm implies that the measurement can vary by this amount, indicating the level of uncertainty.
Correct Answer:
B
— The measurement can vary by 0.01 cm
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Q. If a measurement of time is recorded as 15.0 s with an uncertainty of ±0.5 s, what is the total time range?
A.
14.5 s to 15.5 s
B.
15.0 s to 16.0 s
C.
14.0 s to 15.0 s
D.
15.0 s to 15.5 s
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Solution
Total time range = 15.0 ± 0.5 = 14.5 s to 15.5 s.
Correct Answer:
A
— 14.5 s to 15.5 s
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Q. If a meeting is scheduled for 10 AM and lasts for 2 hours, what time will it end?
A.
11 AM
B.
12 PM
C.
1 PM
D.
10 PM
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Solution
The meeting starts at 10 AM and lasts for 2 hours, so it ends at 12 PM.
Correct Answer:
B
— 12 PM
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Q. If a meeting is scheduled for 1:30 PM and lasts for 1 hour and 15 minutes, when will it end?
A.
2:30 PM
B.
2:45 PM
C.
3:00 PM
D.
3:15 PM
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Solution
The meeting will end at 2:45 PM.
Correct Answer:
B
— 2:45 PM
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Q. If a member of Parliament serves a term of 5 years and is re-elected for another term, how many years will they serve in total?
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Solution
Total years served = 5 years + 5 years = 10 years.
Correct Answer:
B
— 10
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Q. If a member of Parliament serves a term of 5 years, how many terms can a member serve in 20 years?
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Solution
Number of terms = 20 years / 5 years per term = 4 terms.
Correct Answer:
C
— 4
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Q. If a member of the Rajya Sabha serves a term of 6 years, how many members can be elected in a year if 1/3 of the members retire every 2 years and there are 245 members?
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Solution
Members retiring every 2 years = 1/3 of 245 = 81.67, rounded down to 81. Therefore, 41 members can be elected every year.
Correct Answer:
A
— 40
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Q. If a member of the Rajya Sabha serves a term of 6 years, how many members will complete their term in a year if there are 245 members?
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Solution
If 245 members serve 6 years, then 245/6 = 40.83, approximately 41 members complete their term in a year.
Correct Answer:
B
— 41
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Q. If a metal has a work function of 2 eV, what is the minimum wavelength of light required to cause the photoelectric effect?
A.
620 nm
B.
310 nm
C.
1240 nm
D.
500 nm
Show solution
Solution
Using the equation λ = hc/E, where E = 2 eV = 2 * 1.6 x 10^-19 J, we find the minimum wavelength λ = (6.63 x 10^-34 J·s * 3 x 10^8 m/s) / (2 * 1.6 x 10^-19 J) = 310 nm.
Correct Answer:
B
— 310 nm
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Q. If a metal has a work function of 2 eV, what is the threshold wavelength for the photoelectric effect?
A.
620 nm
B.
400 nm
C.
500 nm
D.
300 nm
Show solution
Solution
The threshold wavelength can be calculated using the equation λ = hc/W. Substituting h = 4.14 x 10^-15 eV·s, c = 3 x 10^8 m/s, and W = 2 eV gives λ = 620 nm.
Correct Answer:
A
— 620 nm
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Q. If a metal has a work function of 2.0 eV, what is the maximum kinetic energy of the emitted electrons when illuminated with light of 5.0 eV energy?
A.
3.0 eV
B.
2.0 eV
C.
5.0 eV
D.
0 eV
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Solution
The maximum kinetic energy can be calculated using KE = hf - φ. Here, KE = 5.0 eV - 2.0 eV = 3.0 eV.
Correct Answer:
A
— 3.0 eV
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Q. If a metal has a work function of 3 eV, what is the maximum wavelength of light that can cause photoemission?
A.
400 nm
B.
500 nm
C.
600 nm
D.
700 nm
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Solution
Maximum wavelength (λ) = hc/Φ = (1240 nm·eV)/(3 eV) = 413.33 nm.
Correct Answer:
C
— 600 nm
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Q. If a metal has a work function of 4 eV, what is the minimum wavelength of light required to cause the photoelectric effect?
A.
310 nm
B.
620 nm
C.
1240 nm
D.
2480 nm
Show solution
Solution
The minimum wavelength can be calculated using the equation λ = hc/W. Substituting h = 4.14 x 10^-15 eV·s, c = 3 x 10^8 m/s, and W = 4 eV gives λ = 310 nm.
Correct Answer:
A
— 310 nm
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