JEE Main · PhysicsMedium
A battery of EMF $\varepsilon = 12 \, \text{V}$ and internal resistance $r = 2 \, \Omega$ is connected to an external resistor $R$. If the current in the circuit is $I = 2 \, \text{A}$, what is the value of the external resistance $R$?
- A.$2 \, \Omega$
- B.$6 \, \Omega$
- C.$4 \, \Omega$
- D.$8 \, \Omega$
Show correct answer & step-by-step solution
Correct answer: C — $4 \, \Omega$
Solution
Using , we have $12 = 2(R + 2)$. Dividing by 2 gives $6 = R + 2$, so .
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