Physics Test - ...

The binding energy per nucleon of ${}_{1}H^2$ is $1.1MeV$ and the binding energy per nucleon of ${}_{2}H{e}^4$ is $7MeV$. The energy released when two ${}_{1}H^2$ combines to form ${}_{2}H{e}^4$ is:

The disc of a siren containing $60$ holes rotates at a constant speed of $360rpm$. The emitted sound is in unison with a tuning fork of frequency.

A needle made of bismuth is suspended freely in a magnetic field. The angle which the needle makes with the magnetic field is:

A convex lens made up of a material of refractive index ${\mu }_1$ is immersed in a medium of refractive index ${\mu }_2$ as shown in the figure. The relation between ${\mu }_1$ and ${\mu }_2$ is:

In the photoelectric effect, we assume that photon energy is proportional to its frequency and is completely absorbed by the electrons in a metal. Then, the photoelectric current.

A toy of mass $M_1$ is pulled along a horizontal frictionless surface by the rope of mass $M_2$. A force $F$ is applied to the free end of the rope. the force exerted on the toy is:

During the adiabatic expansion of $2$ moles of a gas, the internal energy was found to have decreased by $100J$. The work done by the gas in this process is:

A point source emits sound equally in all directions in a non-absorbing medium. Two points $P$ and $Q$ are at distances of $2m$ and $3m$, respectively, from the source. The ratio of intensities of the waves at $P$ and $Q$ is:

A photoelectric cell is illuminated by a point source of light $1m$ away. When the source is shifted to $2m$, then

The sodium surface is illuminated by ultraviolet and visible radiations, successively and the stopping potential is determined. This stopping potential is: