An electron enters an electric field with its velocity in the direction of the electric lines of force. Then:
1. | the path of the electron will be a circle. | 2. | the path of the electron will be a parabola. |
3. | the velocity of the electron will decrease. | 4. | the velocity of the electron will increase. |
A charged ball \(B\) hangs from a silk thread \(S,\) which makes an angle \(\theta\) with a large charged conducting sheet \(P,\) as shown in the figure. The surface charge density \(\sigma\) of the sheet is proportional to:
1. \(\sin\theta\)
2. \(\tan\theta\)
3. \(\cos\theta\)
4. \(\cot\theta\)
Three identical positive point charges, as shown are placed at the vertices of an isosceles right-angled triangle. Which of the numbered vectors coincides in direction with the electric field at the mid-point \(M\) of the hypotenuse?
1. \(1\)
2. \(2\)
3. \(3\)
4. \(4\)
1. | \(9000\) N | 2. | \(12000\) N |
3. | \(24000\) N | 4. | \(36000\) N |
Five balls numbered 1 to 5 are suspended using separate threads. Pairs (1, 2), (2, 4), and (4, 1) show electrostatic attraction, while pairs (2, 3) and (4, 5) show repulsion. Therefore ball 1 must be:
1. positively charged.
2. negatively charged.
3. neutral.
4. made of metal.
Two charges \(+2\) C and \(+6\) C are repelling each other with a force of \(12\) N. If each charge is given \(-2\) C of charge, then the value of the force will be:
1. | \(4\) N (attractive) | 2. | \(4\) N (repulsive) |
3. | \(8\) N (repulsive) | 4. | zero |
Two small spheres each having the charge \(+Q\) are suspended by insulating threads of length \(L\) from a hook. If this arrangement is taken in space where there is no gravitational effect, then the angle between the two suspensions and the tension in each will be:
1.
2.
3.
4.
A total charge \(Q\) is broken in two parts \(Q_1\) and \(Q_2\) and they are placed at a distance \(R\) from each other. The maximum force of repulsion between them will occur, when:
1. | \(Q_2=\frac{Q}{R}, Q_1=Q-\frac{Q}{R}\) |
2. | \(Q_2=\frac{Q}{4}, Q_1=Q-\frac{2 Q}{3}\) |
3. | \(Q_2=\frac{Q}{4}, Q_1=\frac{3 Q}{4}\) |
4. | \(Q_1=\frac{Q}{2}, Q_2=\frac{Q}{2}\) |
The electrostatic field due to a charged conductor just outside the conductor is:
1. | zero and parallel to the surface at every point inside the conductor. |
2. | zero and is normal to the surface at every point inside the conductor. |
3. | parallel to the surface at every point and zero inside the conductor. |
4. | normal to the surface at every point and zero inside the conductor. |
Suppose the charge of a proton and an electron differ slightly. One of them is \(-e\), the other is (\(e+\Delta e\)). If the net of electrostatic force and gravitational force between two hydrogen atoms placed at a distance \(d\) (much greater than atomic size) apart is zero, then \(\Delta e\) is of the order of? (Given mass of hydrogen \(m_h = 1.67\times 10^{-27}~\text{kg}\))
1. \(10^{-23}~\text{C}\)
2. \(10^{-37}~\text{C}\)
3. \(10^{-47}~\text{C}\)
4. \(10^{-20}~\text{C}\)