Physics Test - ...

A hydrogen atom is in the excited state of the principal quantum number n. It emits a photon of wavelength' \(\lambda^{\prime}\) when returns to ground state. The value of \(n\) is:

The increase in the width of the depletion region in a \(\mathrm{p-n}\) junction diode is due to:

The earth’s magnetic field at the equator is approximately \(0.4 \mathrm{G}\). Estimate the earth’s dipole moment.

A telescope has an objective lens of focal length 150 cm and an eyepiece of focal length 5 cm. If a 50 m tall tower at a distance of 1 km is observed through this telescope in normal setting, the angle formed by the image of the tower is θ , then θ is close to :

What is the value of instantaneous displacement current in the free space between parallel plate capacitor of capacitance \(1 \mu F\) and the rate of changing potential difference maintain between plates is \(10^{6} {~V} / {s} ?\)

The kinetic energy of the fastest moving photo electron from a metal of work function 2.8 eV is 2 eV. If the frequency of light is doubled, then find the maximum kinetic energy of photo electron.

A body of mass \(M\) is kept on a rough horizontal surface (friction coefficient \(=\mu\) ). A person is trying to pull the body by applying a horizontal force but the body is not moving. The force by the surface on the body is \(F\), where:

When a uranium isotope \({ }_{92}^{235} \mathrm{U}\) is bombarded with a neutron, it generates \({ }_{36}^{89} \mathrm{Kr},\) three neutrons and

The refractive index of the material of a prism is \(\sqrt{2}\) and the angle of the prism is \(30^{\circ}\). One of the two refracting surfaces of the prism is made a mirror inwards, by silver coating. A beam of monochromatic light entering the prism from the other face will retrace its path (after reflection from the silvered surface) if its angle of incidence on the prism is: