The circuit shown here is used to compare the e.m.f. of two cells and . The null point is at C when the galvanometer is connected to E1. When the galvanometer is connected to E2, the null point will be
(1) To the left of C
(2) To the right of C
(3) At C itself
(4) Nowhere on AB
In the Wheatstone's bridge (shown in the figure below) \(X=Y\) and \(A>B\). The direction of the current between \(a\) and \(b\) will be:
1. | from \(a\) to \(b\). |
2. | from \(b\) to \(a\). |
3. | from \(b\) to \(a\) through \(c\). |
4. | from \(a\) to \(b\) through \(c\). |
A resistance of 4 Ω and a wire of length 5 metres and resistance 5 Ω are joined in series and connected to a cell of e.m.f. 10 V and internal resistance 1 Ω. A parallel combination of two identical cells is balanced across 300 cm of the wire. The e.m.f. E of each cell is:
1. 1.5 V
2. 3.0 V
3. 0.67 V
4. 1.33 V
The resistance of an ideal voltmeter is
(1) Zero
(2) Very low
(3) Very large
(4) Infinite
Constantan wire is used in making standard resistances because of its :
(1) Specific resistance is low
(2) Density is high
(3) Temperature coefficient of resistance is negligible
(4) Melting point is high
The net resistance of a voltmeter should be large to ensure that :
1. | It does not get overheated |
2. | It draws excessive current |
3. | It can measure large potential difference |
4. | It does not appreciably change the potential difference to be measured |
A potentiometer consists of a wire of length 4 m and resistance 10 Ω. It is connected to a cell of e.m.f. 2 V. The potential difference per unit length of the wire will be :
(1) 0.5 V/m
(2) 2 V/m
(3) 5 V/m
(4) 10 V/m
In the circuit shown , the reading of the galvanometer is same with switch S open or closed. Then
(1)
(2)
(3)
(4)
In the following Wheatstone bridge . If key K is closed, then the galvanometer will show deflection :
1. In left side
2. In right side
3. No deflection
4. none of the above
A galvanometer having a resistance of \(8~\Omega\) is shunted by a wire of resistance \(2~\Omega\). If the total current is \(1~\text{A}\), the part of it passing through the shunt will be:
1. \(0.25~\text{A}\)
2. \(0.8~\text{A}\)
3. \(0.2~\text{A}\)
4. \(0.5~\text{A}\)