AB is a potentiometer wire of length 100 cm and its resistance is 10 ohms. It is connected in series with a resistance R = 40 ohms and a battery of e.m.f. 2 V and negligible internal resistance. If a source of unknown e.m.f. E is balanced by 40 cm length of the potentiometer wire, the value of E is  

(1) 0.8 V

(2) 1.6 V

(3) 0.08 V

(4) 0.16 V

The measurement of the voltmeter in the following circuit is :

(1) 2.4 V

(2) 3.4 V

(3) 4.0 V

(4) 6.0 V

The potential difference across the 100Ω resistance in the following circuit is measured by a voltmeter of 900 Ω resistance. The percentage error made in reading the potential difference is :

(1) $\frac{10}{9}$

(2) 0.1

(3) 1.0

(4) 10.0

If the ammeter in the given circuit reads 2 A, the resistance R is :

(1) 1 ohm

(2) 2 ohm

(3) 3 ohm

(4) 4 ohm

Two resistances of 400 Ω and 800 Ω are connected in series with a 6-volt battery of negligible internal resistance. A voltmeter of resistance 10,000 Ω is used to measure the potential difference across 400 Ω. The error in the measurement of potential difference in volts approximately is :

(1) 0.01

(2) 0.02

(3) 0.03

(4) 0.05

The length of a wire of a potentiometer is 100 cm, and the emf of its standard cell is E volt. It is employed to measure the e.m.f of a battery whose internal resistance is 0.5 Ω. If the balance point is obtained at l = 30 cm from the positive end, the e.m.f. of the battery is :

(1) $\frac{30E}{100}$

(2) $\frac{30E}{100.5}$

(3) $\frac{30E}{(100-0.5)}$

(4) $\frac{30(E-0.5i)}{100}$, where i is the current in the potentiometer

What is the reading of the voltmeter in the following figure?

(1) 3 V

(2) 2 V

(3) 5 V

(4) 4 V

In a metre bridge experiment, the null point is obtained at 20 cm from one end of the wire when resistance X is balanced against another resistance Y. If X < Y, then where will be the new position of the null point from the same end, if one decides to balance a resistance of 4X against Y 

(1) 50 cm

(2) 80 cm

(3) 40 cm

(4) 70 cm

In given figure, the potentiometer wire AB has a resistance of 5 Ω and length 10 m. The balancing length AM for the emf of 0.4 V is :

(1) 0.4 m

(2) 4 m

(3) 0.8 m

(4) 8 m

If the resistance of voltmeter is 10000Ω and resistance of ammeter is 2Ω then find R when voltmeter reads 12V and ammeter reads 0.1 A :

(1) 118 Ω

(2) 120 Ω

(3) 124 Ω

(4) 114Ω