211. The moment of inertia of a thin rod of mass m and length l,about an axis through its centre of gravity and perpendicular to its length is
ml2/4
ml2/ 6
ml2/8
ml2/12
✅ The correct answer is option D.
Engineering Mechanics MCQs
212. Moment of inertia of a triangular section of base (b) and height (h) about an axis passing through its vertex and parallel to the base, is __________ than that passing through its C.G. and parallel to the base.
nine times
six times
four times
two times
✅ The correct answer is option A.
213. The potential energy of a vertically raised body is __________ the kinetic energy of a vertically falling body.
equal to
less than
greater than
✅ The correct answer is option A.
214. The skidding away of the vehicle on a level circular path can be avoided if the force of friction between the wheels and the ground is __________ the centrifugal force.
less than
greater than
✅ The correct answer is option B.
215. The periodic time of a particle with simple harmonic motion is __________ proportional to the angular velocity.
directly
inversely
✅ The correct answer is option B.
216. A ladder is resting on a smooth ground and leaning against a rough vertical wall. The force of friction will act
towards the wall at its upper and
away from the wall at its upper end
downward at its upper end
upward at its upper en
✅ The correct answer is option D.
217. A circular hole of 50 mm diameter is cut out from a circular disc of 100 mm diameter as shown in the below figure. The centre of gravity of the section will lie
in the shaded area
in the hole
at O
✅ The correct answer is option A.
219. For a self locking machine, the efficiency must be
equal to 50%
less than 50%
greater than 50%
100%
✅ The correct answer is option B.
220. The impact between two lead spheres is approximately equal to an __________ impact.
elastic
inelastic
✅ The correct answer is option B.