Electromagnetic Induction — Physics STD 12 Science — Question

The ratio of longest wavelength and the shortest wavelength observed in the five spectral series of emission spectrum of hydrogen is

Rutherford’s a-particle experiment showed that the atoms have:

Time period of a freely suspended magnet does not depend upon(a) Length of the magnet(b) Pole strength of the magnet(c) Horizontal component of earth's magnetic field(d) Length of the suspension thread

Assertion :  Electron has higher mobility than hole in a semiconductor.
Reason     : Mass of electron is less than the mass of hole. (a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

A body falling vertically downwards under gravity breaks in two parts of unequal masses. The centre of mass of the two parts taken together shifts horizontally towards:

1. Heavier piece.
2. Lighter piece.
3. Does not shift horizontally.
4. Depends on the vertical velocity at the time of breaking.

For ferromagnetic substances:

Photons of energy 6 eV are incident on a metal surface whose work function is 4 eV. The minimum kinetic energy of the emitted photo-electrons will be(a) 0 eV(b) 1 eV(c) 2 eV(d) 10 eV

Displacement current goes through the gap between the plates of a capacitor when the charge of the capacitor:

1. Increases.
2. Decreases.
3. Does not change.
4. Is zero.