Engineering :: Applied Mechanics
211.
A stone weighing 20 N is whirling in a vertical circle at the extremity of a string 100 cm long. The tension in the string will be zero
A.
at the highest position
B.
at the lowest position
C.
at the midway position
D.
at none of the above
Answer: Option A
Explanation:
212.
A force F = 2i + 3j - k is passing through the origin. Its moment about point (1, 1, 0) is
A.
i + j + k
B.
zero
C.
2i + 3j
D.
i - j - k
Answer: Option A
Explanation:
213.
The displacement of a particle under going rectilinear motion along the x-axis is given by x = 2t3 + 21t2 + 60t + 6 metres.
A.
36 m/s2
B.
9 m/s2
C.
27 m/s2
D.
18 m/s2
Answer: Option B
Explanation:
214.
A uniform cylinder of weight W is rolling while slipping on a rough horizontal surface under the influence of a horizontal force. The force of friction between the cylinder and the surface is
A.
Proportional to the coefficient of static friction
B.
Proportional to the coefficient of dynamic friction
C.
Indeterminate
D.
Determinate but depends on the acceleration of the cylinder
Answer: Option D
Explanation:
215.
In a single threaded worm and worm wheel the number of teeth on the worm wheel is 60. The diameter of the effort wheel is 12 cm and that of load drum is 8 cm. The velocity ratio will be
Answer: Option C
Explanation:
216.
A flywheel 200 cm in diameter is rotating at 100 rpm. A point one the rim of the flywheel will not have
A.
angular velocity
B.
centripetal acceleration
C.
tangential acceleration
D.
all of the above
Answer: Option A
Explanation:
217.
A train travels between two stations 15 km apart in 18 minutes. If the train accelerates for a part of journey uniformly followed by uniform retardation, the maximum speed attained by the train during the journey will by
A.
60 km/hr
B.
80 km/hr
C.
100 km/hr
D.
125 km/hr
Answer: Option C
Explanation:
218.
The torque acting on a system is zero. Which of the following will be conserved?
A.
Linear momentum
B.
Angular momentum
C.
Moment of inertia
D.
Angular velocity
Answer: Option B
Explanation:
219.
A apinning ballet dancer draws her arms close to her chest. She will now
A.
spin slower
B.
spin faster
C.
spin at the same rate
D.
stop spinning
Answer: Option A
Explanation:
220.
Two identical weights are dropped simultaneously, one on water and the other in glycerine. Which of the following statement is correct?
A.
The weight will settle quickly in water but slowly in glycerine
B.
The weight will settle slowly in water but quickly in glycerine
C.
The weights will take same time to settle
D.
The water level will fall but glycerine level will rise
Answer: Option A
Explanation:
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