A thin semi-circular conducting ring (PQR) of radius ‘r’ is falling with its plane vertical in a horizontal magnetic field B, as shown in figure. The potential difference developed across the ring when its speed is v, is :-

A bus moving at a speed of 24 m/s begins to slow at a rate of 3 m/s each second. How far does it go before stopping?

If a plant with green leaves is kept in a dark room with only green light on, which one of the following would we observe?

Two springs are connected to block of mass M placed on a frictionless surface as shown below. If both the springs have a spring constant $$k$$​. the frequency of oscillation of the block is:

Y and Z are two partially reflecting glass sheets, a distance $$l$$​ apart in air. White light falls normally on Y. The light emerging from Z is analysed by a spectrometer. A dark band is observed in the spectrometer at a wavelength. The distance $$l$$​ must be equal to:

If a small displacement of a system from the rest position (after getting some energy) results in a small bounded motion about the equilibrium position, then the system is in

The London equation in a super conductor is:

The torque experienced by a magnetic dipole, having dipole moment M, when placed in a uniform magnetic field of intensity B is:

Two coils, each of self inductance L, are closely wound in series such that the sense of their winding is opposite. The equivalent inductance of the combination is:

Which of the following is not the Maxwell's equation?

If the distance between sun and earth were reduced to half its present value, then the number of days in one year would have been