Wave Optics — Physics STD 12 Science — Question

For principal quantum number n = 3, the possible values of orbital quantum number ‘l’ are

(a) 1, 2, 3

(b) 0, 1, 2, 3

(c) 0, 1, 2

(d) –1, 0, +1

In a L - C - R circuit, as the frequency of an alternating current increases the impedance of the circuit.

A point source of light is used in an experiment on photoelectric effect. Which of the following curves best represents the variation of photo current (i) with distance (d) of the source from the emitter

(a) a

(b) b

(c) c

(d) d

A house is served by 220 V supply line in a circuit protected by a 9 ampere fuse. The maximum number of 60 W lamps in parallel that can be turned on, is

(a) 44

(b) 20

(c) 22

(d) 33

Plane figures made of thin wires of resistance R = 50 milli ohm/metre are located in a uniform magnetic field perpendicular into the plane of the figures and which decrease at the rate dB/dt = 0.1 m T/s. Then currents in the inner and outer boundary are. (The inner radius a = 10 cm and outer radius b = 20 cm)

(a) 10– 4 A (Clockwise), 2 × 10– 4 A (Clockwise)

(b) 10– 4 A (Anticlockwise), 2 × 10– 4 A (Clockwise)

(c) 2 × 10– 4 A (clockwise), 10– 4 A (Anticlockwise)

(d) 2 × 10– 4 A (Anticlockwise), 10– 4 A (Anticlockwise)

Magnetic meridian is:

The work-function of a metal is:

Point A is at a lower electrical potential than point B. An electron between them on the line joining them will:

Consider the following statements regarding series grouping of capacitors and select the correct statements.

1. Charge on each capacitor remains same and equals to the main charge supplied by the battery.
2. Potential difference and energy distributes in the reverse ratio of capacitance.
3. Effective capacitance is even less than the least of teh individual capacitances.

The resistance of a wire is   per metre. It is bend in the form of a circle of diameter 2 m. A wire of the same material is connected across its diameter. The total resistance across its diameter AB will be

(a)

(b)

(c) 0.88

(d) 14π