If \(10^9\) electrons move out of a body to another body every second, how much time approximately is required to get a total charge of \(1\) C on the other body?
1. \(200\) years
2. \(100\) years
3. \(150\) years
4. \(250\) years
In Millikan oil drop experiment, a charged drop falls with a terminal velocity v. If an electric field E is applied vertically upwards it moves with terminal velocity 2v in upward direction. If electric field reduces to E/2 then its terminal velocity will be:
1. v/2
2. v
3. 3v/2
4. 2v
The unit of permittivity of free space ε0 is:
1. | Newton metre2 / Coulomb2 |
2. | Coulomb2 /Newton metre2 |
3. | Coulomb2/ (Newton metre)2 |
4. | Coulomb/Newton metre |
The electric field at the equator of a dipole is \(E.\) If the strength of the dipole and distance are now doubled, then the electric field will be:
1. | \(E/2\) | 2. | \(E/8\) |
3. | \(E/4\) | 4. | \(E\) |
A charge \(q\) is placed in a uniform electric field \(E.\) If it is released, then the kinetic energy of the charge after travelling distance \(y\) will be:
1. \(qEy\)
2. \(2qEy\)
3.
4.
The electric field at a distance \(\frac{3R}{2}\) from the centre of a charged conducting spherical shell of radius \(R\) is \(E\). The electric field at a distance \(\frac{R}{2}\) from the centre of the sphere is:
1. \(E\)
2. \(\frac{E}{2}\)
3. \(\frac{E}{3}\)
4. zero
The electric field at a point is:
a. | always continuous |
b. | continuous if there is no charge at that point |
c. | discontinuous only if there is a negative charge at that point |
d. | discontinuous if there is a charge at that point |
1. (a, b)
2. (b, d)
3. (c, d)
4. (a, d)
The figure shows electric field lines in which an electric dipole p is placed as shown. Which of the following statements is correct?
1. | The dipole will not experience any force. |
2. | The dipole will experience a force towards the right. |
3. | The dipole will experience a force towards the left. |
4. | The dipole will experience a force upwards. |
If there were only one type of charge in the universe, then:
1. | \(\oint_{s} \vec{E} \cdot d \vec{s} \neq 0\) on any surface. |
2. | \(\oint_{s} \vec{E} \cdot d \vec{s}=0\)if the charge is outside the surface. |
3. | \(\oint_{s} \vec{E} \cdot d \vec{s}=\frac{q}{\varepsilon_{0}}\) if charges of magnitude q were inside the surface. |
4. | both (2) and (3) are correct. |
The acceleration of an electron due to the mutual attraction between the electron and a proton when they are \(1.6~\mathring{A}\) apart is:
( \(\frac{1}{4 \pi \varepsilon_0}=9 \times 10^9~ \text{Nm}^2 \text{C}^{-2}\) )
1. | \( 10^{24} ~\text{m/s}^2\) | 2 | \( 10^{23} ~\text{m/s}^2\) |
3. | \( 10^{22}~\text{m/s}^2\) | 4. | \( 10^{25} ~\text{m/s}^2\) |