When \(10^{19}\) electrons are removed from a neutral metal plate, the electric charge on it is?
1. | \(-1.6\) C | 2. | \(+1.6\) C |
3. | \(10^{19}\) C | 4. | \(10^{-19}\) C |
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 spherical conductors B and C having equal radii and carrying equal charges in them repel each other with a force F when kept apart at some distance. A third spherical conductor having same radius as that of B but uncharged is brought in contact with B, then brought in contact with C and finally removed away from both. The new force of repulsion between B and C is:
1. F/4
2. 3 F/4
3. F/8
4. 3 F/8
An infinite number of charges, each of charge 1 μC, are placed on the x-axis with co-ordinates x = 1, 2, 4, 8, ....∞. If a charge of 1 C is kept at the origin, then what is the net force acting on 1 C charge?
1. | 9000 N | 2. | 12000 N |
3. | 24000 N | 4. | 36000 N |
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
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 θ with a large charged conducting sheet P, as shown in the figure. The surface charge density σ of the sheet is proportional to:
1. sin θ
2. tan θ
3. cos θ
4. cot θ
Two equal negative charges of charge – q are fixed at the points (0, a) and (0, –a) on the Y-axis. A positive charge Q is released from rest at the point (2a, 0) on the X-axis. The charge Q will:
1. | execute simple harmonic motion about the origin. |
2. | move to the origin and remain at rest. |
3. | move to infinity. |
4. | execute oscillatory but not simple harmonic motion. |
A point charge q is placed at a distance a/2 directly above the centre of a square of side a. The electric flux through the square (i.e. one face) is:
1.
2.
3.
4.
An infinite number of electric charges each equal to 5 nC (magnitude) are placed along the x-axis at x = 1 cm, x = 2 cm, x = 4 cm, x = 8 cm ………. and so on. In the setup if the consecutive charges have opposite sign, then the electric field in Newton/Coulomb at x = 0 is:
1. 12 × 104
2. 24 × 104
3. 36 × 104
4. 48 × 104