Displacement Current

Q. A $100\Omega$ resistance and a capacitor of $100\Omega$ reactance are connected in series across a $220V$ source. When the capacitor is $50\%$ charged, the peak value of the displacement current is

1. $4.4A$
2. $11\sqrt{2}A$
3. $2.2A$
4. $11A$

Q. A point charge is moving along a straight line with a constant velocity $v$. Consider a small area $A$ perpendicular to the direction of motion of the charge. Calculate the displacement current through the area when its distance from the charge is $x$. The value of $x$ is not large so that the electric field at any instant is essentially given by Coulomb's law.

1. $-\frac{qAv}{4\pi x^3}$
2. $\frac{qAv}{2x^3}$
3. $-\frac{qAv}{2\pi x^3}$
4. $\frac{qAv}{4x^3}$

Q. A parallel-plate capacitor with plate area A and separation between the plates d is charged by a constant current i. Consider a plane surface of area $\frac{A}{2}$ parallel to the plates and drawn symmetrically between the plates. Find the displacement current through this area.

1. $\frac{i}{3}$
2. $\frac{i}{2}$
3. $i$
4. $\frac{i}{5}$

Q.

A parallel-plate capacitor with plate area A and separation between the plates d, is charged by a constant current i. Consider a plane surface of area A/2 parallel to the plates and drawn symmetrically between the plates. Find the displacement current through this area.

1. i

2. $\frac{i}{2}$

3. $\frac{i}{3}$

4. $\frac{i}{4}$

Q.

According to Maxwell’s hypothesis, a changing electric field gives rise to

1. An e.m.f.

2. Electric current

3. Magnetic field

4. Pressure radiant

Q. Find the energy stored in a $60\text{cm}$ length of a laser beam operating at $4\text{mW}$.

1. $8\times {10}^{-12}J$
2. $4\times {10}^{-12}J$
3. $8\times {10}^{-14}J$
4. $4\times {10}^{-4}J$

Q. The source of electromagnetic waves can be a charge -

1. Both options $\left(\text{A}\right)$ and $\left(\text{B}\right)$
2. None of these
3. falling freely in an electric field.
4. moving in a circular orbit with constant speed.

Q. A parallel-plate capacitor with plate area A and separation between the plates d is charged by a constant current i. Consider a plane surface of area $\frac{A}{2}$ parallel to the plates and drawn symmetrically between the plates. Find the displacement current through this area.

1. $\frac{i}{3}$
2. $\frac{i}{2}$
3. $i$
4. $\frac{i}{5}$

Q. Given below are two statements.

Statement I : A cyclotron is a device which is used to accelerate a charged particle.

Statement II: Cyclotron frequency depends upon the velocity.

Select the correct option.

1. Statements I and II are true, and Statement II is not the correct explanation for Statement I
2. Statement I is false, but Statement II is true
3. Statements I and II are true, and Statement II is the correct explanation for Statement I
4. Statement I is true, but Statement II is false

Q. Five capacitors are connected as shown in the figure. Initially, all capacitors are uncharged and $S$ is open. When $S$ is closed, then the potential difference between points $\text{M}$ and $\text{N}$ is :
[assume steady state to be achieved after $S$ closes]

1. $14\text{V}$
2. $10\text{V}$
3. $12\text{V}$
4. $15\text{V}$