Which of the following statement is/are incorrect?

Question

Question

The Meter bridge works on the principle of the Wheatstone bridge.
A Meter bridge is used to find the unknown resistance.
A meter bridge is used to find the internal resistance of the battery.
The meter bridge cannot be used to measure the very high or very low resistance.

Answer 1

CONCEPT:

Meter bridge: Meter bridge is instruments based on the principle of Wheatstone bridge and is used to measure an unknown resistance.
In the case of a meter bridge, the resistance wire AC is 100 cm long. Varying the position of tapping point B, the bridge is balanced.
If in the balanced position of bridge AB = l, BC (100 – l) so that

\(\frac{Q}{P} = \frac{{\left( {100 - l} \right)}}{l}\)

Also, \(\frac{P}{Q} = \frac{R}{S} \Rightarrow S = \frac{{\left( {100 - l} \right)}}{l}R\)

EXPLANATION:

From above it clear that the meter bridge works on the principle of Wheatstone bridge. Therefore, option 1 is correct.
The Meter Bridge is instruments based on the principle of Wheatstone bridge and is used to measure an unknown resistance. Therefore option 2 is correct.
A potentiometer is a device which used to measure the internal resistance of the battery. Therefore option 3 is incorrect.
The meter bridge is sensitive when the resistance of all four arms of the bridge are off the same order.
Two parts of the meter bridge wire form two arms with small values of resistance. So other resistances to be compared should also be comparable and hence small. Therefore, option 4 is correct.