Which of following statements are correct ? ltbgt (a) Centre of mass of a body always coincides with the centre of gravity of the body
(b) Central of mass of a body is the point at which the total garvitational torque on the body is zero
(c ) Couple on a body produces both trasnlational and rotation motion in a body
(d) Mechinical advantage greater than one means that small efforts can be used to lift a large load

Options

A. (B) and (D)
B. (A) and (B)
C. (B) and (C)
D. (C) and (D)

Answer

B

Explanation

Centre of mass may lie on centre of gravity. Net torque of gravitational pull is zero about centre of mass. Mechanical advantage `= ("Load")/("Effort") gt 1`
or Load `gt` Effort