Physics Test - ...

The radius R of the soap bubble is doubled under isothermal condition. If T be the surface tension of the soap bubble, the work done in doing so is given by

What is the change in the temperature on Fahrenheit scale and on Kelvin scale, if a iron piece is heated from 30 to 90^oC .

A knife of mass 1 kg slides on a frictionless wedge of mass 5 kg between two frictionless guides. At the instant shown in figure, the spring has initial compression 1m. Ground is also frictionless. Velocity of wedge when knife is about to touch the ground is (assume spring is ideal for large compressions) -

The force required just to move a body up an inclined plane is double the force required just to prevent the body sliding down. If the coefficient of friction is 0.25, then the angle of inclination of the plane is

When the angle of incidence on the material is 60°, the reflected light is completely polarised. The velocity of refracted ray inside the material is

Force acting on a particle moving in a straight line varies with the velocity of the particle as$F=\frac{K}{v}$ . Here K is constant. The work done by this force in time t is

Water is filled in a cylindrical container to a height of 3 m. The ratio of the cross-sectional area of the orifice and the beaker is 0.1. The square of the speed of the liquid coming out from the orifice is (g=10 m s⁻²)

If r be the distance of a point on the axis of a bar magnet from its centre, the magnetic field at this point is proportional to

A single slit of width b is illuminated by a coherent monochromatic light of wavelength λ. If the second and fourth minima in the diffraction pattern at a distance 1 cm from the slit are at 3 cm and 6 cm respectively from the central maximum, what is the width of the central maximum? (i.e. distance between first minimum on either side of the central maximum)

A point charge Q is placed at the corner of a square plate of side a then the flux through the square plate is-