Electric Charges and Fields — Physics STD 12 Science — Question

In a nuclear reaction some mass converts into energy. In this reaction total B.E of reactants when compared with that of products is:

The resistance of the series combination of two resistance is S. When they are joined in parallel the total resistance is P. If S = nP, then the minimum possible value of n is

(a) 4

(b) 3

(c) 2

(d) 1

Electromagnetic waves

A part of a long wire carrying a current i is bent into a circle of radius r as shown in figure. The net magnetic field at the centre O of the circular loop is

(a)

(b)

(c)

(d)

In the circuit diagram shown in the adjoining figure, the resultant capacitance between P and Q is

(a) 47 μF

(b) 3 μF

(c) 60 μF

(d) 10 μ F

The fusion of light elements take place at about the temperatures of about:

If no external voltage is applied across P-N junction, there would be

(a) No electric field across the junction

(b) An electric field pointing from N-type to P-type side across the junction

(c) An electric field pointing from P-type to N-type side across the junction

(d) A temporary electric field during formation of P-N junction that would subsequently disappear

An arbitrary shaped closed coil is made of a wire of length L and a current I ampere is flowing in it. If the plane of the coil is perpendicular to magnetic field , the force on the coil is

(a) Zero

(b) IBL

(c) 2IBL

(d)

How much energy in kilowatt hour is consumed in operating ten 50 watt bulbs for 10 hours per day in a month (30 days).

(a) 1500

(b) 5,000

(c) 15

(d) 150