Class 11th

An ideal gas undergoes four different processes from the same initial state as shown in the figure below: Those process are adiabatic, isothermal, isobaric and isochoric. The cure which represents the adiabatic process among 1, 2, 3 and 4 is:

The angular speed of a fly wheel moving with uniform angular acceleration changes from 1200rpm to 3120 in 16 seconds. The angular acceleration in $\mathrm{r}\mathrm{a}\mathrm{d}/{\mathrm{s}}^2$  is:

The ratio of the distances travelled by a freely falling body in the $1^{\text{st}},2^{\text{nd}},3^{\text{rd}}$ and $4^{\text{th}}$  second:

A body of mass 60g experiences a gravitational force of 3.0 N, when placed at a particular point. The magnitude of the gravitational field intensity at that point is :

The $x-t$ graph of a particle performing simple harmonic motion is shown in the figure. The acceleration of the particle at $\mathrm{t}=2\mathrm{s}$  is:

A satellite is orbiting just above the surface of the earth with period T. If $d$ is the density of the earth and $G$ is the universal constant of gravitation, the quantity $\frac{3\pi }{\mathrm{G}\mathrm{d}}$  represents:

A bullet from a gun is fired on a rectangular wooden block with velocity $u$ . When bullet travels $24\mathrm{c}\mathrm{m}$ through the block along its length horizontally, velocity of bullet become $\frac{u}{3}$ . Then it further penetrates into the block in the same direction before coming to rest exactly at the other end of the block. The total length of the block is:

Choose the correct statement:

Calculate the maximum acceleration of a moving car so that a body lying on the floor of the car remains stationary. The coefficient of static friction between the body and the floor is $0.15\left(\mathrm{g}=10{\mathrm{m}\mathrm{s}}^{-2}\right)$ .

A horizontal bridge is built across a river. A student standing on the bridge throws a small ball vertically upwards with a velocity $4{\mathrm{m}\mathrm{s}}^{-1}$ . The ball strikes the water surface after $4\mathrm{s}$ . The height of bridge above water surface is (Take $\mathrm{g}=$ $10{\mathrm{m}\mathrm{s}}^{-2}$  ):