The actual value of resistance R,shown in the | vedclass

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

Question

(B) Let $R = 30\,\Omega$ be the actual resistance and $R_v$ be the internal resistance of the voltmeter.In the given circuit,the voltmeter is connecte

Vedclass · Accepted Answer

$570$

Vedclass · Answer

(B) Let $R = 30\,\Omega$ be the actual resistance and $R_v$ be the internal resistance of the voltmeter.In the given circuit,the voltmeter is connected in parallel with the resistor $R$.The equivalent resistance $R_{eq}$ of the parallel combination is given by:$R_{eq} = \frac{R \cdot R_v}{R + R_v}$The measured value of resistance is $R_{measured} = R_{eq} = \frac{30 R_v}{30 + R_v}$.According to the problem,the measured value is $5\%$ less than the actual value:$R_{measured} = R 	imes (1 - 0.05) = 30 	imes 0.95 = 28.5\,\Omega$.Equating the two expressions for $R_{measured}$:$\frac{30 R_v}{30 + R_v} = 28.5$$30 R_v = 28.5(30 + R_v)$$30 R_v = 855 + 28.5 R_v$$1.5 R_v = 855$$R_v = \frac{855}{1.5} = 570\,\Omega$.Thus,the internal resistance of the voltmeter is $570\,\Omega$.

Similar Questions

$A$ battery of internal resistance $4\,\Omega$ is connected to a network of resistors as shown in the figure. If maximum power is to be delivered to the network,the magnitude of $R$ in $\Omega$ should be:

The charge flowing through a resistance $R$ varies with time $t$ as $Q = at - bt^2$,where $a$ and $b$ are positive constants. The total heat produced in $R$ is

In the circuit shown, the heat produced in $5 \Omega$ resistance due to current $I_2$ is $50 \text{ J/s}$. Then, the heat generated per second in $2 \Omega$ resistance is (in $\text{ J/s}$)

The equivalent resistance between points $A$ and $B$ of an infinite network of resistances each of $1\,\Omega$ connected as shown,is

The potential difference across the terminals of the battery shown in the figure is ................. $V$. ($r$ = internal resistance of the battery)

Vedclass Test Series

Exam Paper Generator

Online Exam Module