JEE Main Test 9...

Two bodies of masses m and 4m are placed at a distance r. The gravitational potential at a point on the line joining them where the gravitational field is zero, is

A light inextensible string that goes over a smooth fixed pulley as shown in the figure connects two blocks of masses 0.36 kg and 0.72 kg. Taking, g = 10 ms^-2, find the work done (in joule) by string on the block of mass 0.36 kg during the first second after the system is released from rest.

Let S_k be the sum of an infinite GP series whose first term k is k and common ratio is k/(k + 1) (k> 0). Then, the value of 

In a reversible ideal engine, 650 J of heat comes from source of 450 K, heat rejected to sink at 225 K is

A piece of ice (heat capacity = 2100 J kg ^-1° C^-1 and latent heat = 3.36 × 10⁵J kg ^-1) of mass m gram is at –5°C at atmospheric pressure. It is given 420 J of heat, so that the ice starts melting. Finally when the ice-water mixture is in equilibrium, it is found that 1 g of ice has melted. Assuming there is no other heat exchange in the process, the value of m is

A student is allowed to select atmost n books from a collection of (2n + 1) books. If the number of ways in which he can do this, is 64, then the value of n is

A cylinder of height 20 m is completely filled with water. The velocity of efflux of water (in ms^-1) through a hole on the side wall of the cylinder near its bottom, is

One mole of an ideal gas in initial state A undergoes a cyclic process ABCA, as shown in the figure. Its pressure at A is p₀. Choose the correct option (s) from the following

A Carnot engine whose low temperature reservoir is at 7°C has an efficiency of 50%. It is desired to increase the efficiency to 70%. By how many degrees should the temperature of the high temperature reservoir be increased?

For |χ| < 1, the constant term in the expansion of