An unknown resistance R_1 is connected in ser | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) In a meter bridge,the balancing condition is given by $\frac{P}{Q} = \frac{l}{100-l}$,where $P$ and $Q$ are resistances in the two gaps and $l$ is

Vedclass · Accepted Answer

$20$

Vedclass · Answer

(C) In a meter bridge,the balancing condition is given by $\frac{P}{Q} = \frac{l}{100-l}$,where $P$ and $Q$ are resistances in the two gaps and $l$ is the balance length.Case $1$: $R_1$ is in series with $10 \,\Omega$ in one gap,and $R_2$ is in the other gap. The balance point is at $50 \, cm$.$\frac{R_1 + 10}{R_2} = \frac{50}{100-50} = \frac{50}{50} = 1$$\Rightarrow R_2 = R_1 + 10$  --- (Equation $1$)Case $2$: The $10 \,\Omega$ resistance is removed,so only $R_1$ remains in the first gap. The balance point shifts to $40 \, cm$.$\frac{R_1}{R_2} = \frac{40}{100-40} = \frac{40}{60} = \frac{2}{3}$$\Rightarrow 3R_1 = 2R_2$ --- (Equation $2$)Substitute Equation $1$ into Equation $2$:$3R_1 = 2(R_1 + 10)$$3R_1 = 2R_1 + 20$$R_1 = 20 \,\Omega$.

Similar Questions

In a meter bridge experiment,to minimize an error due to contact resistance,

Consider a $72\, cm$ long wire $AB$ as shown in the figure. The galvanometer jockey is placed at $P$ on $AB$ at a distance $x\, cm$ from $A$. The galvanometer shows zero deflection. The value of $x$,to the nearest integer,is ..... $cm$.

In a metre bridge experiment (see figure), the positions of the cell, $E$, and galvanometer, $G$, are interchanged. We shall observe in the galvanometer:

In a metre bridge experiment,the null point is obtained at $20 \,cm$ from the left end of the wire,when resistance $X$ is balanced against another resistance $Y$ $(X < Y)$. To balance a resistance $4X$ against $Y$,the new position of the null point from the same end will be: (in $\,cm$)

Vedclass Test Series

Exam Paper Generator

Online Exam Module