Which of the following graph correctly represents the variation of mobility of electrons with applied electric field (E) in a metallic conductor?
1. | 2. | ||
3. | 4. |
In the circuit shown in the figure, the effective resistance between A and B is:
1. 2
2. 4
3. 6
4. 8
The drift velocity of free electrons in a conductor is \(v\) when a current \(i\) is flowing in it. If both the radius and current are doubled, then the drift velocity will be:
1. \(v\)
2. \(\frac{v}{2}\)
3. \(\frac{v}{4}\)
4. \(\frac{v}{8}\)
A battery has e.m.f. 4 V and internal resistance r. When this battery is connected to an external resistance of 2 ohm, a current of 1 ampere flows in the circuit. How much current will flow if the terminals of the battery are connected directly?
1. | 1 A | 2. | 2 A |
3. | 4 A | 4. | Infinite |
The equivalent resistance between \(A\) and \(B\) is:
1. \(3~\Omega\)
2. \(6~\Omega\)
3. \(9~\Omega\)
4. \(12~\Omega\)
The current I as shown in the circuit will be:
1. 10 A
2.
3.
4.
A meter bridge is set up to determine unknown resistance x using a standard 10 resistor. The galvanometer shows the null point when the tapping key is at a 52 cm mark. End corrections are 1 cm and 2 cm respectively for end A and B. Then the value of x is:
1. 10.2
2. 10.6
3. 10.8
3. 11.1
The current through the 5 resistor is:
1. 3.2 A
2. 2.8 A
3. 0.8 A
4. 0.2 A
The current in a wire varies with time according to the relation i= (3+2t) A. The amount of charge passing a cross section of the wire in the time interval t=0 to t=4.0 sec would be: (where t is time in seconds)
1. | 28 C | 2. | 30.5 C |
3. | 8 C | 4. | 82 C |
In the circuit shown, the value of each of the resistances is r. The equivalent resistance of the circuit between terminals A and B will be:
1. (4/3)r
2. 3r/2
3. r/3
4. 8r/7