Physics Test - ...

Closed O.P. and an open O.P. of same length produce 2 beats/sec. When they are set into vibrations together in fundamental mode. The length of open pipe is now halved and that of closed pipe is doubled. The number of beats produced will be:

In a \(p-n\) junction diode, change in temperaturedue to heating:

A system has two charges \(\mathrm{q_{A}=2.5 \times 10^{-7} C}\) and \(\mathrm{q_{B}=-2.5 \times 10^{-7} C}\) located at points \(\mathrm{A:(0,0,-15 \mathrm{~cm})}\) and \(\mathrm{B:(0,0,+15 \mathrm{~cm})}\) respectively. What are the total charge and electric dipole moment of the system?

White light is passed through a double slit and interference is observed on a screen \(1.5 \mathrm{~m}\) away. The separation between the slits is \(0.3 \mathrm{~mm}\). The first violet and red fringes are formed \(2.0 \mathrm{~mm}\) and \(3.5 \mathrm{~mm}\) away from the central whitefringes. The difference in wavelengths of red and violet light is ...... \(\mathrm{nm}\).

In the given figure, the value of \(\mathrm{V}_0\) will be \(\mathrm{V}\).

The surface of a metal is illuminated with the light of \(400 \mathrm{~nm}\). The kinetic energy of the ejected photoelectrons was found to be \(1.68 \mathrm{eV}\). The work function of the metal is: \((h c=1240 \mathrm{eV} \mathrm{nm})\)

A body cools from \(80^{\circ} C\) to \(60^{\circ}\) in 5 minutes. The temperature for the surrounding is \(20^{\circ} C\). The time it takes to cool from \(60^{\circ} C\) to \(40^{\circ} C\) is 

Which of the following method is used to measure the mass of planets?

Monochromatic light is refracted from air into glass of refractive index \(\mu\). The ratio of the wavelengths of the incident and refracted waves is: