Physics

A rod of mass m and length L is hinged at its top end. If the rod is in equilibrium making an angle of 30° with the vertical when a horizontal force F is applied as shown in figure, then the value of F is:

An ideal gas undergoes a cyclic process whose indicator diagram is as shown in the figure. Find the work done by the gas in 1 complete cycle.

A ray of light is reflected by two perpendicular plane mirrors as shown. The angle θ is equal to:

A proton of mass m and charge q enters a region of uniform magnetic field of a magnitude B with a velocity v directed perpendicular to the magnetic field. It moves in a circular path and leaves the magnetic field after completing a quarter of a circle. The time spent by the proton inside the magnetic field is proportional to:

If the intensity of light in double slit experiment from slit 1 and slit 2 are I₀ and 25I₀ respectively, find the ratio of intensities of light at minima and maxima in the interference pattern.

Two trains are approaching each other on the same track with velocity 100 km/h and 50 km/h. When they are at a distance of 300 km from each other, a bird starts flying from train 1 towards train 2. When the bird reaches train 2, it instantly reverses its direction and flies again towards train 1. This process continues till the bird is trapped between the trains when they collide. If the bird always travels at a constant speed 200 km/h, the total distance the bird flies is:

If temperature of a liquid is increased, choose the correct option regarding change in its surface tension and viscosity.

The speed of sound in a particular gas at a temperature 27°C is 340 m/s. Then, the speed of sound in the same gas at a temperature 90°C is:

A point source surrounded by vacuum emits an electromagnetic wave of frequency of 900 kHz. If the power emitted by the source is 15 W, the amplitude of the electric field of the wave (in 10^-3V/m) at a distance 15 km from the source is :
( (1 / 4πε₀) = 9*10⁹ Nm²/C² and speed of light in vacuum = 3 * 10⁸ ms^-1)

A composite rod made up of two conductors of resistivity ρ₁ and ρ₂ is show in the figure. If face A and B are connected to a battery, find the resistance of the rod.