Q. A torque of 30 Nm is applied to a wheel. If the radius of the wheel is 0.5 m, what is the force applied tangentially at the edge of the wheel?
A.
15 N
B.
30 N
C.
60 N
D.
75 N
Show solution
Solution
Torque (τ) = F × r, thus F = τ / r = 30 Nm / 0.5 m = 60 N.
Correct Answer: C — 60 N
Learn More →
Q. A torque of 40 Nm is required to rotate a wheel. If the radius of the wheel is 0.4 m, what is the force applied tangentially?
A.
100 N
B.
80 N
C.
60 N
D.
40 N
Show solution
Solution
Force = Torque / Radius = 40 Nm / 0.4 m = 100 N.
Correct Answer: B — 80 N
Learn More →
Q. A torque of 5 Nm is applied to a wheel. If the radius of the wheel is 0.25 m, what is the force applied tangentially?
A.
10 N
B.
20 N
C.
5 N
D.
15 N
Show solution
Solution
Torque (τ) = F × r, thus F = τ / r = 5 Nm / 0.25 m = 20 N.
Correct Answer: A — 10 N
Learn More →
Q. A torque of 5 N·m is applied to a wheel with a moment of inertia of 2 kg·m². What is the angular acceleration of the wheel?
A.
2.5 rad/s²
B.
5 rad/s²
C.
10 rad/s²
D.
1 rad/s²
Show solution
Solution
Angular acceleration α = Torque/I = 5 N·m / 2 kg·m² = 2.5 rad/s².
Correct Answer: A — 2.5 rad/s²
Learn More →
Q. A torque of 50 Nm is applied to a wheel with a radius of 0.25 m. What is the force applied at the edge of the wheel?
A.
100 N
B.
200 N
C.
250 N
D.
300 N
Show solution
Solution
Force = Torque / Radius = 50 Nm / 0.25 m = 200 N.
Correct Answer: B — 200 N
Learn More →
Q. A torque of 50 Nm is applied to a wheel with a radius of 0.5 m. What is the force applied tangentially to the wheel?
A.
100 N
B.
50 N
C.
25 N
D.
75 N
Show solution
Solution
Torque (τ) = Force (F) × Radius (r) => F = τ / r = 50 Nm / 0.5 m = 100 N.
Correct Answer: A — 100 N
Learn More →
Q. A torque of 50 Nm is created by a force acting at a distance of 2 m. What is the force applied?
A.
20 N
B.
25 N
C.
30 N
D.
35 N
Show solution
Solution
Force = Torque / Distance = 50 Nm / 2 m = 25 N.
Correct Answer: B — 25 N
Learn More →
Q. A torque τ is applied to a rigid body with moment of inertia I. If the body starts from rest, what is the angular displacement θ after time t?
A.
(1/2)(τ/I)t^2
B.
(τ/I)t^2
C.
(1/2)(I/τ)t^2
D.
(I/τ)t^2
Show solution
Solution
Using the equation of motion for rotation, θ = (1/2)αt^2, where α = τ/I, thus θ = (1/2)(τ/I)t^2.
Correct Answer: A — (1/2)(τ/I)t^2
Learn More →
Q. A torque τ is applied to a rotating object with moment of inertia I. If the object starts from rest, what is its angular acceleration α?
A.
τ/I
B.
I/τ
C.
Iτ
D.
τI
Show solution
Solution
From Newton's second law for rotation, τ = Iα, thus α = τ/I.
Correct Answer: A — τ/I
Learn More →
Q. A train is moving at 72 km/h and a bird flies in the opposite direction at 18 km/h. What is the speed of the bird relative to the train?
A.
54 km/h
B.
72 km/h
C.
90 km/h
D.
18 km/h
Show solution
Solution
Relative speed = Speed of train + Speed of bird = 72 km/h + 18 km/h = 90 km/h.
Correct Answer: A — 54 km/h
Learn More →
Q. A train is moving at 72 km/h and passes a platform in 20 seconds. What is the length of the train?
A.
100 m
B.
200 m
C.
300 m
D.
400 m
Show solution
Solution
Length of train = Speed × Time = (72 km/h × (1000 m/1 km) / (3600 s/1 h)) × 20 s = 400 m.
Correct Answer: B — 200 m
Learn More →
Q. A train is moving at 72 km/h and passes a platform in 20 seconds. What is the length of the platform if the train is 180 meters long?
A.
200 m
B.
300 m
C.
400 m
D.
500 m
Show solution
Solution
Speed of train = 72 km/h = 20 m/s. Time = 20 s. Distance = Speed × Time = 20 m/s × 20 s = 400 m. Length of platform = 400 m - 180 m = 220 m.
Correct Answer: B — 300 m
Learn More →
Q. A train is moving at 72 km/h and passes a platform in 30 seconds. What is the length of the platform if the train is 200 meters long?
A.
200 m
B.
300 m
C.
400 m
D.
500 m
Show solution
Solution
Speed in m/s = 72 * (1000/3600) = 20 m/s. Distance = Speed × Time = 20 m/s × 30 s = 600 m. Length of platform = 600 m - 200 m = 400 m.
Correct Answer: B — 300 m
Learn More →
Q. A train is moving at 90 km/h and a bird flies at 45 km/h in the opposite direction. What is the speed of the bird relative to the train?
A.
135 km/h
B.
45 km/h
C.
90 km/h
D.
135 km/h
Show solution
Solution
Relative speed = Speed of train + Speed of bird = 90 km/h + 45 km/h = 135 km/h.
Correct Answer: A — 135 km/h
Learn More →
Q. A train leaves a station and travels at 90 km/h. Another train leaves the same station 30 minutes later and travels at 120 km/h. How far from the station will they meet?
A.
90 km
B.
120 km
C.
150 km
D.
180 km
Show solution
Solution
Let the distance be d. Time taken by first train = d/90. Time taken by second train = d/120. Setting up the equation gives d = 150 km.
Correct Answer: C — 150 km
Learn More →
Q. A train leaves a station at 70 km/h. Another train leaves the same station 30 minutes later at 90 km/h. How far from the station will they meet?
A.
70 km
B.
90 km
C.
100 km
D.
110 km
Show solution
Solution
Let the distance be d. Time taken by first train = d/70, second train = d/90. They meet when d/70 = d/90 + 0.5. Solving gives d = 100 km.
Correct Answer: C — 100 km
Learn More →
Q. A train leaves a station at 80 km/h and another train leaves the same station 30 minutes later at 100 km/h. How far from the station will they meet?
A.
100 km
B.
120 km
C.
150 km
D.
180 km
Show solution
Solution
Let the time taken by the first train be t hours. Distance = speed * time. 80t = 100(t - 0.5). Solving gives t = 2 hours, so distance = 80 * 2 = 160 km.
Correct Answer: B — 120 km
Learn More →
Q. A train moving at 72 km/h overtakes a man walking at 6 km/h in the same direction. How fast does the train appear to be moving to the man?
A.
66 km/h
B.
72 km/h
C.
78 km/h
D.
84 km/h
Show solution
Solution
Relative speed = Speed of train - Speed of man = 72 km/h - 6 km/h = 66 km/h.
Correct Answer: A — 66 km/h
Learn More →
Q. A train moving at 72 km/h passes a man walking at 6 km/h in the same direction. How fast does the train appear to be moving to the man?
A.
66 km/h
B.
72 km/h
C.
78 km/h
D.
84 km/h
Show solution
Solution
Relative speed = Speed of train - Speed of man = 72 km/h - 6 km/h = 66 km/h.
Correct Answer: A — 66 km/h
Learn More →
Q. A train moving at 72 km/h passes a platform 300 m long. How long does it take to cross the platform completely?
A.
10 seconds
B.
15 seconds
C.
20 seconds
D.
25 seconds
Show solution
Solution
Total distance = Length of train + Length of platform. If length of train is L, time = (L + 300)/20 m/s. Assuming L = 300 m, time = (300 + 300)/20 = 30 seconds.
Correct Answer: B — 15 seconds
Learn More →
Q. A train moving at a speed of 72 km/h applies brakes and comes to a stop in 5 seconds. What is the acceleration of the train?
A.
-4 m/s²
B.
-2 m/s²
C.
-3 m/s²
D.
-1 m/s²
Show solution
Solution
First, convert speed to m/s: 72 km/h = 20 m/s. Using a = (v - u)/t = (0 - 20)/5 = -4 m/s².
Correct Answer: A — -4 m/s²
Learn More →
Q. A train moving with a speed of 60 km/h applies brakes and comes to a stop in 5 seconds. What is the magnitude of its acceleration?
A.
-3 m/s²
B.
-2 m/s²
C.
-1 m/s²
D.
-4 m/s²
Show solution
Solution
First, convert speed to m/s: 60 km/h = 60/3.6 = 16.67 m/s. Using the formula: acceleration = (final velocity - initial velocity) / time = (0 - 16.67) / 5 = -3.33 m/s², approximately -3 m/s².
Correct Answer: A — -3 m/s²
Learn More →
Q. A train moving with a speed of 72 km/h applies brakes and comes to a stop in 10 seconds. What is the acceleration of the train?
A.
-2 m/s²
B.
-3 m/s²
C.
-4 m/s²
D.
-5 m/s²
Show solution
Solution
First convert speed to m/s: 72 km/h = 20 m/s. Using the formula: acceleration = (final velocity - initial velocity) / time = (0 - 20) / 10 = -2 m/s².
Correct Answer: B — -3 m/s²
Learn More →
Q. A train moving with a speed of 72 km/h applies brakes and comes to a stop in 10 seconds. What is the magnitude of its acceleration?
A.
-2 m/s²
B.
-3 m/s²
C.
-4 m/s²
D.
-5 m/s²
Show solution
Solution
First convert speed to m/s: 72 km/h = 20 m/s. Using the formula: acceleration = (final velocity - initial velocity) / time = (0 - 20) / 10 = -2 m/s².
Correct Answer: C — -4 m/s²
Learn More →
Q. A train of mass 1000 kg is moving with a velocity of 36 km/h. What is its kinetic energy?
A.
500 J
B.
1000 J
C.
1800 J
D.
2000 J
Show solution
Solution
First convert velocity to m/s: 36 km/h = 10 m/s. K.E. = (1/2)mv² = (1/2)(1000 kg)(10 m/s)² = 50000 J.
Correct Answer: C — 1800 J
Learn More →
Q. A train travels 120 km at a uniform speed. If it takes 2 hours to complete the journey, what is the speed of the train?
A.
50 km/h
B.
60 km/h
C.
70 km/h
D.
80 km/h
Show solution
Solution
Speed = distance / time = 120 km / 2 h = 60 km/h.
Correct Answer: B — 60 km/h
Learn More →
Q. A train travels at a speed of 72 km/h. How far will it travel in 30 minutes?
A.
12 km
B.
18 km
C.
24 km
D.
36 km
Show solution
Solution
Distance = speed × time = 72 km/h × 0.5 h = 36 km.
Correct Answer: B — 18 km
Learn More →
Q. A train travels at a speed of 72 km/h. How long will it take to cover a distance of 180 km?
A.
2 hours
B.
2.5 hours
C.
3 hours
D.
3.5 hours
Show solution
Solution
Time = distance / speed. Convert speed to m/s: 72 km/h = 20 m/s. Time = 180 km / 72 km/h = 2.5 hours.
Correct Answer: C — 3 hours
Learn More →
Q. A train travels at a speed of 90 km/h and a car at 60 km/h. If they start from the same point and travel in the same direction, how far apart will they be after 1 hour?
A.
30 km
B.
20 km
C.
10 km
D.
40 km
Show solution
Solution
Relative speed = 90 - 60 = 30 km/h. Distance apart after 1 hour = 30 km.
Correct Answer: A — 30 km
Learn More →
Q. A transformer operates on the principle of electromagnetic induction. If the primary coil has 100 turns and the secondary coil has 50 turns, what is the relationship between the primary and secondary voltages?
A.
V_primary = 2 * V_secondary
B.
V_primary = 0.5 * V_secondary
C.
V_primary = V_secondary
D.
V_primary = 4 * V_secondary
Show solution
Solution
The voltage ratio in a transformer is given by the turns ratio. Therefore, V_primary/V_secondary = N_primary/N_secondary = 100/50 = 2, which means V_primary = 2 * V_secondary.
Correct Answer: A — V_primary = 2 * V_secondary
Learn More →
Showing 1171 to 1200 of 5000 (167 Pages)
