Wave Optics — Physics STD 12 Science — Question

In the depletion region of a diode:

A 20 cm length of a certain solution causes right-handed rotation of 38°. A 30cm length of another solution causes left-handed rotation of 24°. The optical rotation caused by 30cm length of a mixture of the above solutions in the volume ratio 1 : 2 is

(a) Left handed rotation of 14°	(b) Right handed rotation of 14°
(c) Left handed rotation of 3°	(d) Right handed rotation of 3°

An insulator plate is passed between the plates of a capacitor. Then, current:

The combined capacity of the parallel combination of two capacitors is four times their combined capacity when connected in series. This means that

(a) Their capacities are equal	(b) Their capacities are 1 μF and 2 μF
(c) Their capacities are 0.5 μF  and 1 μF	(d) Their capacities are infinite

A conducting rod is moved with a constant velocity v in a magnetic field. A potential difference appears across the two ends:

If  is the intensity of the principal maximum in the single slit diffraction pattern, then what will be its intensity when the slit width is doubled

(a)

(b)

(c) 2

(d) 4

The polarisation is measured in:

A constant current i is maintained in a solenoid. Which of the following quantities will increase if an iron rod is inserted in the soleniod along axis?

1. Magnetic field at the centre.
2. Mangetic flux linked with the solenoid.
3. Self-inductance of the solenoid.
4. Rate of Joule heating.

Which is the correct relation for forbidden energy gap in conductor, semi conductor and insulator

(a)

(b)

(c)

(d)