Two resistances R and 2R are connected in parallel in an electric circuit. The thermal energy developed in R and 2R are in the ratio
1. 1 : 2
2. 2 : 1
3. 1 : 4
4. 4 : 1.
A uniform wire of resistance \(50~\Omega\) \(\) is cut into \(5\) equal parts. These parts are now connected in parallel. The equivalent resistance of the combination is:
1. | \(2~\Omega\) \(\) | 2. | \(10~\Omega\) \(\) |
3. | \(250~\Omega\) \(\) | 4. | \(6250~\Omega\) |
Consider the following two statements:
Statement I: | Kirchhoff’s junction law follows from the conservation of charge. |
Statement II: | Kirchhoff’s loop law follows from the conservative nature of the electric field. |
1. | Both Statement I and Statement II are correct. |
2. | Statement I is correct but Statement II is incorrect. |
3. | Statement I is incorrect but Statement II is correct. |
4. | Both Statement I and Statement II are incorrect. |
Two non-ideal batteries are connected in series. Consider the following statements:
A: | The equivalent emf is larger than either of the two emfs. |
B: | The equivalent internal resistance is smaller than either of the two internal resistances. |
1. | Each of A and B is correct. |
2. | A is correct but B is wrong. |
3. | B is correct but A is wrong. |
4. | Each of A and B is wrong. |
Two non-ideal batteries are connected in parallel. Consider the following statements:
Statement-I: | The equivalent emf is smaller than either of the two emfs. |
Statement-II: | The equivalent internal resistance is smaller than either of the two internal resistances. |
1. | Both Statement I and Statement II are correct. |
2. | Statement I is correct but Statement II is wrong. |
3. | Statement II is correct but Statement I is wrong. |
4. | Both Statement I and Statement II are wrong |
Electrons are emitted by a hot filament and are accelerated by an electric field as shown in the figure. The two stops at the left ensure that the electron beam has a uniform cross-section.
(a) The speed of the electron is more at B than at A.
(b) The electric current is from left to right.
(c) The magnitude of the current is larger at B than at A.
(d) The current density is more at B than at A
Choose the correct option
1. (a) only
2. (b), (c)
3. (c), (d)
4. (a), (d)
When no current is passed through a conductor,
(a) | the free electrons do not move. |
(b) | the average speed of a free electron over a large period of time is zero. |
(c) | the average velocity of a free electron over a large period of time is zero. |
(d) | the average of the velocities of all the free electrons at an instant is zero. |
Choose the correct option:
1. | (a) only | 2. | (b), (c) |
3. | (c), (d) | 4. | (a), (d) |
Which of the following quantities do not change when a resistor connected to a battery is heated due to the current?
(a) | drift speed |
(b) | resistivity |
(c) | resistance |
(d) | the number of free electrons |
Choose the correct option:
1. | (d) only | 2. | (b), (c) |
3. | (c), (d) | 4. | (a), (d) |
As the temperature of a conductor increases, its resistivity and conductivity change. The ratio of resistivity to conductivity:
(a) | increases |
(b) | decreases |
(c) | remains constant |
(d) | may increase or decrease depending on the actual temperature |
Choose the correct option:
1. (a) only
2. (b), (c)
3. (c), (d)
4. (a), (d)
(a) the charge crossing in a given time interval
(b) drift speed
(c) current density
(d) free-electron density
Choose the correct option
1. (a) only
2. (b), (c)
3. (c), (d)
4. (a), (d)