A diver at a depth of 12 m in water $\\mu=\\dfrac{4}{3}$ sees the sky in a cone of semiverticale
angle :

A particle performs a uniform circular motion with an angular momentum L. If the frequency of
the particle s motion is doubled and its KE is halved, the angular momentum becomes

A radioactive substance has a half-life of 60 minutes. During 3 hour, the fraction of atoms that
have decayed would be

A convex lens of focal length 30 cm produces 5 times magnified real image of an
object. What is the object distance ?

The frequency of oscillation of current in the inductance is

1.56 X $10^5$J of heat is conducted through a 2 $m^2$ wall of 12 cm thick in one hour.
Temperature difference between the two sides of the wall is 20 °C.
The thermal conductivity of the material of the wall is (in W $m^{-1} K^{-1}$)

A stone of relative density K is released from rest on the surface of a lake. If viscous
effects are ignored, the stone sinks in water with an acceleration of

A block B is pushed momentarily along a horizontal surface with an initial velocity v. If $\\mu$ is
the coefficient of sliding friction between B and the surface, block B will come to rest after a time

A body falling from a height h travels 40 m in the last two seconds of its fall to ground. The
height h in metres is (use g = 10 $ms^{-2}$)

A lens is placed between a source of light and a wall. It forms images of area A1 and A2 on
the wall, for its two different positions. The are of the source obtained is