The Velocity Ratio (VR) of a block and tackle system of two pulleys with the effort in the upward direction is:

1. 1
2. 2
3. 3
4. 4

From the figure given below, the refractive index of medium B with respect to medium A (_Aμ_B) is:

1. $\dfrac{\text {sin }45\degree}{\text {sin }30\degree} \\[1em]$
2. $\dfrac{\text {sin }30\degree}{\text {sin }45\degree} \\[1em]$
3. $\dfrac{\text {sin }45\degree}{\text {sin }60\degree} \\[1em]$
4. $\dfrac{\text {sin }60\degree}{\text {sin }45\degree} \\[1em]$

A fast-moving cyclist stops pedalling on reaching a hilly track. If he continues to move with the acquired energy, then assuming no loss of energy:

1. his kinetic energy remains constant at all times.
2. his potential energy remains constant at all times.
3. his total mechanical energy continuously increases.
4. his total mechanical energy remains constant.

The distance (V) of a virtual image formed by a lens of focal length 15 cm never exceeds a certain finite value, then this value will be:

1. less than 15 cm
2. between 15 cm to 30 cm
3. less than or equal equal to 30 cm
4. less than or equal to 15 cm