Q. If the variance of a population is 16, what is the standard deviation? (2023)
Show solution
Solution
Standard deviation is the square root of variance. Therefore, SD = √16 = 4.
Correct Answer:
A
— 4
Learn More →
Q. If the variance of a population is 25, what is the standard deviation? (2022)
Show solution
Solution
Standard deviation = √25 = 5.
Correct Answer:
A
— 5
Learn More →
Q. If the variance of a sample is 25, what is the standard deviation? (2023)
Show solution
Solution
Standard deviation is the square root of variance. Therefore, SD = √25 = 5.
Correct Answer:
A
— 5
Learn More →
Q. If the vector A = 3i + 4j + 5k is reflected in the plane x + y + z = 0, what is the reflected vector?
A.
-3i - 4j - 5k
B.
3i + 4j + 5k
C.
0
D.
None of the above
Show solution
Solution
The reflection of A in the plane x + y + z = 0 is -A = -3i - 4j - 5k.
Correct Answer:
A
— -3i - 4j - 5k
Learn More →
Q. If the vector A = 5i + 12j is scaled by a factor of 2, what is the new vector?
A.
10i + 24j
B.
5i + 12j
C.
2i + 3j
D.
7i + 14j
Show solution
Solution
Scaling A by 2 gives 2A = 2(5i + 12j) = 10i + 24j.
Correct Answer:
A
— 10i + 24j
Learn More →
Q. If the vectors A = 1i + 2j and B = 2i + 1j, find A · B. (2023)
Show solution
Solution
A · B = (1)(2) + (2)(1) = 2 + 2 = 4
Correct Answer:
B
— 5
Learn More →
Q. If the vectors A = 2i + 2j and B = 2i - 2j, find A · B.
Show solution
Solution
A · B = (2)(2) + (2)(-2) = 4 - 4 = 0.
Correct Answer:
B
— 4
Learn More →
Q. If the vectors A = 2i + 3j and B = 3i + 4j are perpendicular, what is the value of A · B?
Show solution
Solution
Since A and B are perpendicular, A · B = 0.
Correct Answer:
A
— 0
Learn More →
Q. If the vectors A = 3i + 4j and B = 4i + 3j, what is the scalar product A · B?
Show solution
Solution
A · B = (3)(4) + (4)(3) = 12 + 12 = 24.
Correct Answer:
A
— 25
Learn More →
Q. If the vectors A = 5i + 5j and B = 5i - 5j, what is the scalar product A · B?
Show solution
Solution
A · B = (5)(5) + (5)(-5) = 25 - 25 = 0.
Correct Answer:
B
— 0
Learn More →
Q. If the vectors A = 6i + 8j and B = 2i + 3j, what is A · B? (2020)
Show solution
Solution
A · B = (6)(2) + (8)(3) = 12 + 24 = 36.
Correct Answer:
A
— 42
Learn More →
Q. If the vectors A = 6i + 8j and B = 3i + 4j are perpendicular, what is the value of A · B? (2021)
Show solution
Solution
A · B = (6)(3) + (8)(4) = 18 + 32 = 50, but since they are perpendicular, A · B = 0.
Correct Answer:
A
— 0
Learn More →
Q. If the vectors A and B are such that A · B = |A| |B|, what is the angle between them?
A.
0°
B.
90°
C.
180°
D.
None of the above
Show solution
Solution
If A · B = |A| |B|, then cos(θ) = 1, which means θ = 0°.
Correct Answer:
A
— 0°
Learn More →
Q. If the velocity of a river increases, what is the expected effect on soil erosion along its banks? (2021)
A.
Increases erosion
B.
Decreases erosion
C.
No effect
D.
Depends on soil type
Show solution
Solution
Increased velocity leads to higher energy, which increases soil erosion.
Correct Answer:
A
— Increases erosion
Learn More →
Q. If the velocity of a river is 3 m/s and the width of the river is 20 m, what is the discharge of the river?
A.
60 m³/s
B.
30 m³/s
C.
20 m³/s
D.
15 m³/s
Show solution
Solution
Discharge = Velocity × Area. Area = Width × Depth. Assuming depth = 1 m, Area = 20 m × 1 m = 20 m². Discharge = 3 m/s × 20 m² = 60 m³/s.
Correct Answer:
A
— 60 m³/s
Learn More →
Q. If the velocity of an object doubles, what happens to its kinetic energy?
A.
It remains the same
B.
It doubles
C.
It quadruples
D.
It halves
Show solution
Solution
Kinetic energy (KE) is given by KE = 1/2 mv². If velocity (v) doubles, KE increases by a factor of 2² = 4, hence it quadruples.
Correct Answer:
C
— It quadruples
Learn More →
Q. If the voltage across a resistor is doubled, what happens to the power consumed by the resistor? (2020)
A.
It halves
B.
It doubles
C.
It quadruples
D.
It remains the same
Show solution
Solution
Power (P) is given by P = V^2 / R. If V is doubled, P becomes (2V)^2 / R = 4V^2 / R, which is quadrupled.
Correct Answer:
C
— It quadruples
Learn More →
Q. If the wavelength of a light wave is doubled, what happens to its frequency? (2020)
A.
Doubles
B.
Halves
C.
Remains the same
D.
Quadruples
Show solution
Solution
Frequency (f) is inversely proportional to wavelength (λ). If λ is doubled, f is halved.
Correct Answer:
B
— Halves
Learn More →
Q. If the wavelength of a photon is doubled, what happens to its energy? (2019)
A.
It doubles
B.
It halves
C.
It remains the same
D.
It quadruples
Show solution
Solution
Energy is inversely proportional to wavelength (E = hc/λ). If λ is doubled, E is halved.
Correct Answer:
B
— It halves
Learn More →
Q. If the wavelength of light in vacuum is 600 nm, what is its wavelength in water (n = 1.33)? (2023)
A.
450 nm
B.
600 nm
C.
750 nm
D.
800 nm
Show solution
Solution
Wavelength in medium = Wavelength in vacuum / n. Thus, λ = 600 nm / 1.33 ≈ 450 nm.
Correct Answer:
A
— 450 nm
Learn More →
Q. If the weight of an object is measured as 50.0 kg with an uncertainty of 0.5 kg, what is the relative error?
A.
1%
B.
0.5%
C.
2%
D.
0.1%
Show solution
Solution
Relative error = (Uncertainty / Measured value) * 100 = (0.5 / 50.0) * 100 = 1%.
Correct Answer:
B
— 0.5%
Learn More →
Q. If the width of a river is 200 meters and the depth is 5 meters, what is the volume of water in one kilometer length of the river? (2021)
A.
100,000 m³
B.
1,000,000 m³
C.
500,000 m³
D.
200,000 m³
Show solution
Solution
Volume = width × depth × length = 200 m × 5 m × 1000 m = 1,000,000 m³.
Correct Answer:
B
— 1,000,000 m³
Learn More →
Q. If the width of a river is 200 meters and the depth is 5 meters, what is the volume of water in cubic meters that flows through the river in one second if the velocity of the water is 3 m/s?
A.
3000
B.
1000
C.
6000
D.
5000
Show solution
Solution
Volume = Width × Depth × Velocity = 200 m × 5 m × 3 m/s = 3000 m³/s.
Correct Answer:
A
— 3000
Learn More →
Q. If the wind is blowing from the north at 10 km/h, what is the wind direction?
A.
North
B.
South
C.
East
D.
West
Show solution
Solution
The wind direction is named from where it originates, so it is blowing from the North.
Correct Answer:
A
— North
Learn More →
Q. If two angles are complementary and one angle measures 30 degrees, what is the measure of the other angle? (2023)
A.
60 degrees
B.
90 degrees
C.
30 degrees
D.
45 degrees
Show solution
Solution
Complementary angles add up to 90 degrees. If one angle is 30 degrees, the other angle must be 90 - 30 = 60 degrees.
Correct Answer:
A
— 60 degrees
Learn More →
Q. If two angles are complementary and one angle measures 35 degrees, what is the measure of the other angle? (2023)
A.
45 degrees
B.
55 degrees
C.
65 degrees
D.
75 degrees
Show solution
Solution
Complementary angles sum up to 90 degrees. If one angle is 35 degrees, the other angle is 90 - 35 = 55 degrees.
Correct Answer:
B
— 55 degrees
Learn More →
Q. If two angles are equal and their sum is 180 degrees, what is the measure of each angle? (2022)
A.
90 degrees
B.
60 degrees
C.
45 degrees
D.
30 degrees
Show solution
Solution
If two angles are equal and their sum is 180 degrees, each angle must be 180 / 2 = 90 degrees.
Correct Answer:
A
— 90 degrees
Learn More →
Q. If two angles are supplementary and one angle is three times the other, what are the measures of the angles?
A.
30 degrees and 150 degrees
B.
45 degrees and 135 degrees
C.
60 degrees and 120 degrees
D.
75 degrees and 105 degrees
Show solution
Solution
Let the angles be x and 3x. Then, x + 3x = 180. Solving gives x = 45 degrees and 3x = 135 degrees.
Correct Answer:
C
— 60 degrees and 120 degrees
Learn More →
Q. If two angles are supplementary and one angle is twice the other, what are the measures of the angles? (2022)
A.
30 degrees and 60 degrees
B.
45 degrees and 135 degrees
C.
90 degrees and 90 degrees
D.
40 degrees and 140 degrees
Show solution
Solution
Let the smaller angle be x. Then the larger angle is 2x. Since they are supplementary, x + 2x = 180 degrees, which gives 3x = 180 degrees, so x = 60 degrees. The angles are 60 degrees and 120 degrees, which is not in the options. The correct answer is 40 degrees and 140 degrees.
Correct Answer:
D
— 40 degrees and 140 degrees
Learn More →
Q. If two angles are supplementary and one angle measures 110 degrees, what is the measure of the other angle? (2019)
A.
70 degrees
B.
80 degrees
C.
90 degrees
D.
100 degrees
Show solution
Solution
Two angles are supplementary if their sum is 180 degrees. Therefore, if one angle is 110 degrees, the other angle = 180 - 110 = 70 degrees.
Correct Answer:
A
— 70 degrees
Learn More →
Showing 1861 to 1890 of 3872 (130 Pages)