Wave Optics — Physics STD 12 Science — Question

Energy of electrons can be increased by allowing them

(a) To fall through electric potential	(b) To move in high magnetic field
(c) To fall from great heights	(d) To pass through lead blocks

A ray of light passes through an equilateral glass prism in such a manner that the angle of incidence is equal to the angle of emergence and each of these angles is equal to 3/4 of the angle of the prism. The angle of deviation is

(a) 45°

(b) 39°

(c) 20°

(d) 30°

Figure shows electric field lines in which an electric dipole p is placed as shown. Which of the following statements is correct?

If the current is halved in a coil, then the energy stored is how much times the previous value

(a)

(b)

(c) 2

(d) 4

Which of the following statements is correct in case of Thomson’s atomic model?

A particular emission line, detected in the light from a galaxy, has a wavelength  , where    is the proper wavelength of the line. The galaxy distance from us

(a) 1.6

(b) 0.97

(c) 2.4

(d) 1.62

State the approximate potential difference applied between the anode and filament cathode ray tube.

The magnifying power of a simple microscope can be increased, if we use eye-piece of

(a) Higher focal length	(b) Smaller focal length
(c) Higher diameter	(d) Smaller diameter

The magnetic field due to the earth is closely equivalent to that due to

(a) A large magnet of length equal to the diameter of the earth

(b) A magnetic dipole placed at the centre of the earth

(c) A large coil carrying current

(d) Neither of the above

A condenser of capacitance 10 μF has been charged to 100 volts. It is now connected to another uncharged condenser in parallel. The common potential becomes 40 volts. The capacitance of another condenser is

(a) 15 μF

(b) 5 μF

(c) 10 μF

(d) 16.6 μF