Moment of a Force NEET Questions

Physics - Rotational Motion

Moment of a Force MCQ Questions


13.
A force of 20 N acts at an angle of 30° with a position vector of magnitude 2 m drawn from the axis. The torque about the axis is:
A.
40 N·m
B.
20 N·m
C.
10 N·m
D.
20√3 N·m
😑 View Answer Rough Work Error
ANSWER :
B. 20 N·m
14.
A wrench of length 30 cm is used to tighten a nut. If a force of 50 N is applied perpendicular to the wrench at its end, the torque produced is:
A.
1500 N·m
B.
150 N·m
C.
15 N·m
D.
1.5 N·m
😑 View Answer Rough Work Error
ANSWER :
C. 15 N·m
15.
A force F = (3î + 4ĵ) N acts at the point r = (2î) m. The torque about the origin is:
A.
8 k̂ N·m
B.
6 k̂ N·m
C.
(6î + 8ĵ) N·m
D.
10 k̂ N·m
😑 View Answer Rough Work Error
ANSWER :
A. 8 k̂ N·m
16.
A force F = (2î − 3ĵ + 4k̂) N acts at the position r = (î + 2ĵ − k̂) m. The torque about the origin (in N·m) is:
A.
(5î − 6ĵ − 7k̂)
B.
(5î + 6ĵ − 7k̂)
C.
(−5î + 6ĵ + 7k̂)
D.
(5î − 6ĵ + 7k̂)
😑 View Answer Rough Work Error
ANSWER :
A. (5î − 6ĵ − 7k̂)
17.
If r = (î + ĵ + k̂) m and F = (3î + 2ĵ + k̂) N, the magnitude of the torque about the origin is approximately:
A.
Zero
B.
√14 N·m
C.
√6 N·m
D.
3 N·m
😑 View Answer Rough Work Error
ANSWER :
C. √6 N·m
18.
The torque of a force 7î + 3ĵ − 5k̂ about the origin acting at a particle whose position vector is î − ĵ + k̂ is:
A.
2î + 12ĵ + 10k̂
B.
−2î + 12ĵ + 10k̂
C.
2î − 12ĵ − 10k̂
D.
2î + 10ĵ + 12k̂
😑 View Answer Rough Work Error
ANSWER :
A. 2î + 12ĵ + 10k̂