Question

If balnace point is obtained at 35cm in a meter bridge the resistances in left and right gaps are in the ratio of

Answer 1

Given:

Balance point is obtained at 35 cm in a meter bridge .

To find:

Ratio of resistances in left and right gaps.

Concept:

Metre Bridge is a device which works on the principle of Balanced Wheatstone Bridge. It helps us to calculate the resistance of an unknown resistor in presence of a known shunt resistance.

It consists of the following parts :

• Unknown Resistance

• Shunt Resistance

• 1 metre or 100 cm long wire

Calculation:

Since balance point is obtained at 35 cm , we can consider Balanced Wheatstone Bridge condition such that the adjacent resistances will be in ratio.

Let the resistances be P and Q and l be the balance point :

$\therefore \: \dfrac{P}{Q} = \dfrac{l}{(100 - l)}$

$= > \: \dfrac{P}{Q} = \dfrac{35}{(100 - 35)}$

$= > \: \dfrac{P}{Q} = \dfrac{35}{65}$

$= > \: \dfrac{P}{Q} = \dfrac{7}{13}$

So the resistances will be in the ratio of :

$\boxed{ \red{ \bold{ \large{P : Q = 7 : 13}}}}$

Answer 2

Answer:

Explanation:

Applying the concept of Wheatstone bridge for metre bridge:

P/Q=l/(100-l) where P,Q are the resistances and l is balanced point.

So,P:Q=35/(100-35)=7:13

Hope you understood