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 :

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 $P\ne R$, the reading of the galvanometer is same with switch S open or closed. Then 

(1) $I_R=I_G$

(2) $I_P=I_G$

(3) $I_Q=I_G$

(4) $I_Q=I_R$

In the following Wheatstone bridge $P/Q=R/S$. If key K is closed, then the galvanometer will show deflection :

(1) In left side

(2) In right side

(3) No deflection

(4) In either side

A galvanometer having a resistance of 8 ohms is shunted by a wire of resistance 2 ohms. If the total current is 1 amp, the part of it passing through the shunt will be :

(1) 0.25 amp

(2) 0.8 amp

(3) 0.2 amp

(4) 0.5 amp

In a potentiometer experiment, the galvanometer shows no deflection when a cell is connected across 60 cm of the potentiometer wire. If the cell is shunted by a resistance of 6 Ω, the balance is obtained across 50 cm of the wire. The internal resistance of the cell is 

(1) 0.5 Ω

(2) 0.6 Ω

(3) 1.2 Ω

(4) 1.5 Ω

A voltmeter of resistance 1000 Ω gives full-scale deflection when a current of 100 mA flow through it. The shunt resistance required across it to enable it to be used as an ammeter reading 1 A at full-scale deflection is :

(1) 10000 Ω

(2) 9000 Ω

(3) 222 Ω

(4) 111 Ω

In the circuit given below, the e.m.f. of the cell is 2 volt and the internal resistance is negligible. The resistance of the voltmeter is 80 ohm. The reading of the voltmeter will be:                                 
1. 0.80 volt

2. 1.60 volt

3. 1.33 volt

4. 2.00 volt

A voltmeter has resistance of 2000 ohms and it can measure upto 2V. If we want to increase its range to 10 V, then the required resistance in series will be 

(1) 2000 Ω

(2) 4000 Ω

(3) 6000 Ω

(4) 8000 Ω