Physics Test 18...

A stone is tied to a string of length l and is whirled in a vertical circle with the other end of the string as the centre. At a certain instant of time, the stone is at its lowest position and has a speed u. The magnitude of the change in velocity as it reaches a position where the string is horizontal (g being acceleration due to gravity) is

An equilateral triangle ABC formed from a uniform wire has two small identical beads initially located at A. The triangle is set rotating about the vertical axis AO. Then the beads are released from rest simultaneously and allowed to slide down, one along AB and the other along AC as shown. Neglecting frictional effects, the quantities that are conserved as the beads slide down, are

A uniform spherical shell gradually shrinks maintaining its shape. The gravitational potential at the centre

A beam of metal supported at the two edges is loaded at the centre. The depression at the centre is proportional to

A jar is filled with two non-mixing liquids 1 and 2 having densities p₁ and, p₂ respectively. A solid ball, made of a material of density p₃, is dropped in the jar. It comes to equilibrium in the position shown in the figure. Which of the following is true for p₁, p₂ and p₃?

In a room where the temperature is 30^oC, a body cools from 61^oC to 59^oC in 4 minutes. The time (in minutes) taken by the body to cool from 51^oC to 49^oC will be :

In a thermodynamic process, fixed mass of a gas is changed in such a manner that the gas release 20 J of heat and 8 J of work was done on the gas. If the initial internal energy of the gas was 30 J, the final internal energy will be

The molar heat capacities of a mixture of two gases at constant volume is 13R/6. The ratio of number of moles of the first gas to the second is 1 : 2. The respective gases may be

In S.H.M., the ratio of kinetic energy at mean position to the potential energy when the displacement is half of the amplitude is

In a resonance tube with tuning fork of frequency 512 Hz, first resonance occurs at water level equal to 30.3 cm and second resonance occurs at 63.7 cm. The maximum possible error in the speed of sound is