A meter bridge is set up to determine unknown resistance \(x\) using a standard \(10~\Omega\) 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. \(10.2~\Omega\)
2. \(10.6~\Omega\)
3. \(10.8~\Omega\)
4. \(11.1~\Omega\)

An unknown resistance R₁ is connected in series with a resistance of 10 Ω. This combinations is connected to one gap of a metre bridge while a resistance R₂ is connected in the other gap. The balance point is at 50 cm. Now, when the 10 Ω resistance is removed the balance point shifts to 40 cm. The value of R₁ is (in ohm) 

(1) 60

(2) 40

(3) 20

(4) 10

For measurement of potential difference, the potentiometer is preferred in comparison to the voltmeter because:

1. the potentiometer is more sensitive than the voltmeter.

2. the resistance of the potentiometer is less than
    the voltmeter.

3. the potentiometer is cheaper than the voltmeter.

4. the potentiometer does not take current from the circuit.

A potentiometer is an ideal device of measuring potential difference because

(1) It uses a sensitive galvanometer

(2) It does not disturb the potential difference it measures

(3) It is an elaborate arrangement

(4) It has a long wire hence heat developed is quickly radiated