Class 11th

Two moles of helium gas are taken over the cycle ABCDA as shown below in P-T diagram. Assuming the gas to be ideal, the work done on the gas in taking from A to B is

An incompressible liquid flows through a horizontal tube as shown in the following figure. The velocity v of the fluid is

A point mass m is placed at a distance 2R from the centre of the shell of mass M and radius R. The gravitational force exerted by shell on the point mass is

When a soap bubble is illuminated by source of white light, it appears coloured. This is due to

Magnification at least distance of distinct vision by simple microscope having focal length 2.5 cm is

A set of 16 tuning forks are so arranged that each produce 4 beats with the previous one. If the frequency of last tuning fork is double that of first, the frequency of third tuning fork is

A pipe open at both ends produces a note of fundamental frequency V₁. When the pipe is kept with (1/3)^rd of its length in water, it produces a note of frequency V₂.The value of V₁/ V₂ is

A string of linear density 0.4 kg/m is stretched with force of 1000 N. A transverse wave is set up along it. The speed of the wave is

The latent heat of vaporisation of substance is

The bulk modulus of a spherical object is B. If it is subjected to uniform pressure P, the fractional decrease in surface area is