Physics NCERT Exemplar Solutions Class 12th Chapter Eleven

A vessel contains 14 g of nitrogen gas at a temperature of 27°C. The amount of heat to be transferred to the gas to double the r.m.s speed of its molecules will be:

Take R = 8.32 J mole1 k1.

Consider a cylindrical tank of radius 1m is filled with water. The top surface of water is at 15m front the bottom of the cylinder. There is a hole on the wall of a cylinder at a height of 5m from the bottom. A force of 5 * 10⁵N is applied an the top surface of water using a piston. The speed of ifflux from the hole will be:

(given atmospheric pressure P_A = 1.01 * 10⁵Pa, density of water ${\rho }_w=1000kg/m^3$  and gravitational acceleration g = 10m/s²)

Assume there are two identical simple pendulum clocks. Clock – 1 is placed on the earth and Clock – 2 is placed on a space station located at a height h above the earth surface. Clock – 1 and Clock – 2 operate at time periods 4s and 6s respectively. Then the value of h is – (consider radius of earth R_E = 6400km and g on earth 10 m/s²)

A bullet of mass 200g having initial kinetic energy 90 J is shot inside a long swimming pool as shown in the figure. If it's kinetic energy reduces to 40 J within 1s, the minimum length of the pool, the bullet has to travel so that it completely comes to rest is

A uniform metal chain of mass m length 'L' passes over a massless and frictionless pulley. It is released from rest with a part of its length $\text{'}\mathcal{l}\text{'}$ is hanging on one side and rest of its length $\text{'}L-\mathcal{l}\text{'}$ is hanging on the other side of the pully. At a certain point of time, when $\mathcal{l}=\frac{L}{x},$ the acceleration of the chain is $\frac{g}{2}.$ The value of x is__________.

A pressure-pump has a horizontal tube of cross sectional area 10cm2 for the outflow of water at a speed of 20 m/s. The force exerted on the vertical wall just in front of the tube which stops water horizontally flowing out of the tube, is:

[given : density of water = 1000 kg/m³]

At time t = 0 a particle starts travelling from a height $7\widehat{z}cm$ in a plane keeping z coordinate constant. At any instant of time it's position along the $\widehat{x}and\widehat{y}$ directions are defined as 3t and 5t3 respectively. At t = 1s acceleration of the particle will be

Consider the efficiency of carnot's engine is given by $\eta =\frac{\alpha \beta }{sin\theta }loge\frac{\beta x}{kT},$ where and are constants. If T is temperature, k is Boltzmann constant, is angular displacement and x has the dimensions of length. Then, choose the incorrect option

The specific heat of water $=4200\mathrm{J}{\mathrm{k}\mathrm{g}}^{-1}{\mathrm{K}}^{-1}$ and the latent heat of ice $=3.4*{10}^5\mathrm{J}{\mathrm{k}\mathrm{g}}^{-1}$ . 100 grams of ice at $0^{\circ }\mathrm{C}$ is placed in $200\mathrm{g}$ of water at ${25}^{\circ }\mathrm{C}$ . The amount of ice that will melt as the temperature of water reaches $0^{\circ }\mathrm{C}$ is close to (in grams):

Given figure shows few data points in a photo electric effect experiment for a certain metal. The minimum energy for ejection of electron from its surface is: (Plancks constant $\mathrm{h}=6.62\times {10}^{-34}\mathrm{J}.\mathrm{s}$ )