The drift velocity of free electrons in a conductor is when a current is flowing in it. If both the radius and current are doubled, then the drift velocity will be:
1. | 2. | ||
3. | 4. |
1. | A | 2. | A |
3. | A | 4. | Infinite |
The current as shown in the circuit will be:
1. | 2. | ||
3. | 4. |
A meter bridge is set up to determine unknown resistance using a standard resistor. The galvanometer shows the null point when the tapping key is at a cm mark. End corrections are cm and cm respectively for end and . Then the value of is:
1.
2.
3.
4.
The resistivity of iron is 1 × 10–7 ohm – m. The resistance of iron wire of particular length and thickness is 1 ohm. If the length and the diameter of wire both are doubled, then the resistivity in ohm – m will be :
1. 1 × 10–7
2. 2 × 10–7
3. 4 × 10–7
4. 8 × 10–7
The resistivity of a wire :
1. | Increases with the length of the wire |
2. | Decreases with the area of cross-section |
3. | Decreases with the length and increases with the cross-section of the wire |
4. | None of the above statement is correct |
Drift velocity varies with the intensity of the electric field as per the relation:
1.
2.
3.
4.
In a conductor 4 coulombs of charge flows for 2 seconds. The value of electric current will be :
1. 4 volts
2. 4 amperes
3. 2 amperes
4. 2 volts
The specific resistance of a wire is ρ, its volume is 3 m3 and its resistance is 3 ohms, then its length will be
1.
2.
3.
4.
When a piece of aluminum wire of finite length is drawn through a series of dies to reduce its diameter to half its original value, its resistance will become :
1. Two times
2. Four times
3. Eight times
4. Sixteen times