Question

156. Which of the following statements are correct?
(a) Centre of mass of a body always coincides withthe centre of gravity of the body.
(b) Centre of mass of a body is the point at whichthe total gravitational torque on the body is zero
(c) A couple on a body produce both translationaland rotational motion in a body.
(d) Mechanical advantage greater than one meansthat small effort can be used to lift a large load.
(1) (b) and (d) (2) (a) and (b)
(3) (b) and (c) (4) (c) and (d)

Answer 1

the answer for your question is option (2)

Answer 2

Out of the given sentences, the sentences which are correct are:

• Centre of mass of a body is the point at which total gravitational torque on the body is zero. So, the option (b) is a correct statement.
• When mechanical advantage is greater than one, that means, on application of a small amount of effort we can lift a larger amount of load. So, the option (d) is the correct statement.
• Thus, option (1) that is, (b) and (d) are correct.