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Easy
Question
A hollow sphere of mass M (in kg) and radius R (in m) is rotating with an angular frequency 
(in rad/sec). It suddenly stops rotating and 75% of the K.E. is converted into heat energy. If s joule/kg–kelvin is the specific heat of the material of the sphere, the rise of temperature of the sphere is
The correct answer is:
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Window A is a plane sheet of glass 4 millimeters thick, as shown. Window B is a sandwich consisting of two extremely thin layers of glass separated by an air gap 2 millimeters thick, as shown. If the thermal conductivities of glass and air are 0.8 watt/meter°C and 0.025 watt/meter°C, respectively, then the ratio of the heat flow through window A to the heat flow through window B for same temperature difference from 
and for same time duration T sec area is same for window A and B.
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An air chamber of volume V has a neck area of cross-section ‘a’ into which a ball of mass m can move up and down without friction. If the ball is press down a little and released then find the time period of oscillation of ball. Here air is ideal & its temperature remains constant & the isothermal. Bulk modulus of air is B.
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A block P of mass m is placed on a frictionless horizontal surface. Another block Q of same mass is kept on P and connected to the wall with the help of a spring of spring constant k as shown in the figure. 
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Two particles each of mass M are connected by a massless rod of length l. The rod is lying on the smooth sufrace. If one of the particle is given an impulse MV as shown in the figure then angular velocity of the rod would be
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One quarter sector is cut from a uniform circular disc of radius R. This sector has mass M. It is made to rotate about a line perpendicular to its plane and passing through the centre of the original disc. Its moment of inertia about the axis of rotation is
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