AIEEE 2012 PYQ Mock Test

Hydrogen atom is excited from ground state to another state with principal quantum number equal to 4. Then the number of spectral lines in the emission spectra will be:

A coil is suspended in a uniform magnetic field, with the plane of the coil parallel to the magnetic lines of force. When a current is passed through the coil it starts oscillating; it is very difficult to stop. But if an aluminium plate is placed near to the coil, it stops. This is due to:

The mass of a spaceship is $1000\text{kg}$. It is to be launched from the earth's surface out into free space. The value of '$g$ ' and '$R$ ' (radius of earth) are $10{\text{m/s}}^2$ and $6400\text{km}$ respectively. The required energy for this work will be:

Helium gas goes through a cycle $ABCDA$ (consisting of two isochoric and two isobaric lines) as shown in figure. The pressure and volume at $A$ are $P_0,V_0$ and at $C$ are $2P_0,2V_0$. Efficiency of this cycle is nearly:

In Young's double slit experiment, one of the slit is wider than other, so that the amplitude of the light from one slit is double of that from other slit. If $I_m$ be the maximum intensity, the resultant intensity $I$ when they interfere at phase difference $\varphi$ is given by: