Question

The balancing point in a meter bridge is 44
cm. If the resistances in the gaps are
interchanged, the new balance point is​

Answer 1

Answer:

56

Explanation:

when resistance gaps are interchanged balancing length also gets interchanged

Answer 2

Answer:

The new balance point is at position 26.67 cm.

Explanation:

The balance condition for the meter bridge is

$\dfrac RS=\dfrac{l}{100-l}$.

where,

• $R$ and $S$ are the resistance of the portion of the wire on left and right of the balanced point respectively.

• $l$ is the length of the wire of the meter bridge up to the balance point from its one end.

Given that, $l=44\ cm$.

Therefore, using the balance condition,

$\dfrac RS=\dfrac{44}{(100-44)}=\dfrac{44}{56}=\dfrac{11}{14}\\\Rightarrow R=\dfrac{11}{14}S.$

When the resistances $R$ and $S$ are interchanged, let the new balance point be at length $l'$.

The new balance condition is given by

$\dfrac SR = \dfrac{l'}{100-l'}\\\dfrac{S}{\frac{11}{4}S}=\dfrac{l'}{100-l'}\ \ \ \ \text{Using (1).} \\\dfrac{4}{11}=\dfrac{l'}{100-l'}\\4(100-l')=11l'\\400-4l'=11l'\\(11+4)l'=400\\15l'=400\\l'=\dfrac{400}{15}=26.67\ cm.$

It is the position of the new balance point.