A dc source of emf , E_1 = 100 , V and intern | vedclass

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

Question

(C) For no current to pass through the battery $E_2$,the potential difference across the external resistor $R$ must be equal to the $emf$ of the batte

Vedclass · Accepted Answer

$4$

Vedclass · Answer

(C) For no current to pass through the battery $E_2$,the potential difference across the external resistor $R$ must be equal to the $emf$ of the battery $E_2$.Let $I$ be the current flowing through the circuit containing $E_1$,$r$,and $R$.According to Ohm's law,the current in the circuit is $I = \frac{E_1}{R + r}$.The potential difference across the resistor $R$ is $V = I 	imes R = \frac{E_1 	imes R}{R + r}$.For no current to flow through the branch containing $E_2$,we must have $V = E_2$.Substituting the given values: $\frac{100 	imes R}{R + 0.5} = 90$.Dividing both sides by $10$: $\frac{10 	imes R}{R + 0.5} = 9$.$10R = 9(R + 0.5)$.$10R = 9R + 4.5$.$R = 4.5 \, \Omega$.

Similar Questions

The neutral temperature of a thermocouple is defined as the temperature at which:

Which of the four resistances $P, Q, R$ and $S$ generate the greatest amount of heat when a current flows from $A$ to $B$?

In the given circuit,find the charge on the capacitors.

In the given network, the potential difference between the points $B$ and $D$ is

All wires have the same resistance $r$. The equivalent resistance between $A$ and $B$ is $R$. Now,if the keys $K_1$ and $K_2$ are closed,what will be the new equivalent resistance?

Vedclass Test Series

Exam Paper Generator

Online Exam Module