In figure two positive charges q ₂ and q₃ fixed along the y-axis, exert a net electric force in the + x- direction on a charge q₁ fixed along the x-axis. If a positive charge Q is added at (x, 0), the force on q₁

1

(a)

shall increase along the positive x-axis

(b)

shall decrease along the positive x-axis

(c)

shall point along the negative x-axis

(d)

shall increase but the direction changes because of the intersection of Q with q₂ and q₃

A hemisphere is uniformly charged. The electric field at a point on a diameter away from the centre is directed

1

(a)

perpendicular to the diameter

(b)

parallel to the diameter

(c)

at an angle tilted towards the diameter

(d)

at an angle tilted away from the diameter

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

1

(a)

The dipole will not experience any force.

(b)

The dipole will experience a force towards right.

(c)

The dipole will experience a force towards left.

(d)

The dipole will experience a force upwards.

Figure shows some equipotential lines distributed in space. A charged object is moved from point A to point B.

1

(a)

The work done in Fig. (i) is the greatest

(b)

The work done in Fig. (ii) is least

(c)

The work done is the same in Fig. (i), Fig.(ii) and Fig. (iii)

(d)

The work done in Fig. (iii) is greater than Fig. (ii) but equal to that in

Two cells of emfs approximately 5 V and l0 V are to be accurately compared using a potentiometer of length 400 cm.

1

(a)

The battery that runs the potentiometer should have voltage of 8V

(b)

The battery of potentiometer can have a voltage of 15 V and R adjusted so that the potential drop across the wire slightly exceeds 10 V

(c)

The first portion of 50 cm of wire itself should have a potential drop of 10 V

(d)

Potentiometer is usually used for comparing resistances and not voltages

A square of side L metres lies in the xy-plane in a region, where the magnetic field is given by B \(=B_{0}(2 \hat{\mathbf{i}}+3 \hat{\mathbf{j}}+4 \hat{\mathbf{k}}) \mathrm{T}\), where B_o is constant. The magnitude of flux passing through the square is

1

(a)

\(2 B_{0} L^{2} \mathrm{~Wb}\)

(b)

\(3 B_{0} L^{2} \mathrm{~Wb}\)

(c)

\(4 B_{0} L^{2} \mathrm{~Wb}\)

(d)

\(\sqrt{29} B_{0} L^{2} \mathrm{~Wb}\)

If the rms current in a 50 Hz AC circuit is 5 A, the value of the current 1/300 s after its value becomes zero is

1

(a)

5\(\sqrt{2} A\)

(b)

5\(\sqrt{3/2}\) A

(c)

5 / 6 A

(d)

5 / \(\sqrt{2} A\)

The ratio of contributions made by the electric field and magnetic field components to the intensity of an EM wave is

1

(a)

C : 1

(b)

C² : 1

(c)

1 : 1

(d)

\(\sqrt{c}: 1\)

When a nucleus in an atom undergoes a radioactive decay, the electronic energy levels of the atom

1

(a)

do not change for any type of radioactivity

(b)

change for a and β-radioactivity but not for γ-radioactivity 

(c)

change for a-radioactivity but not for others

(d)

change for β-radioactivity but not for others

In fusion reaction occurring in the sun,

1

(a)

hydrogen is converted into carbon

(b)

hydrogen and helium are converted into carbon and other heavier metals/elements

(c)

helium is converted into hydrogen

(d)

hydrogen is converted into helium