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. (a) and (b)
B. (b) and (c)
C. (c) and (d)
D. (b) and (d)

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`
Load `gt` Effort