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Grade 12Electric Current

A dry cell of emf 1.6V and internal resistance 0.1 ohm is connected to a resistor of resistance R ohm . If the current drawn from the cell is 2A, then (i) What is the voltage drop across R? (ii) What is the energy dissipation in the resistor?

Profile image of Anshuman Mishra
9 Years agoGrade 12
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1 Answer

Profile image of Prasanna Vibhandik
9 Years ago
first of all ;
The current flowing through the circuit will be:
\frac{V}{R+r}
(As the net resistance is R+r)
Now the potential drop across the resistor R ohm will be:
V – Ir
(where r is internal resistance)
SO, the energy dissipated in the ‘R’ resistor would be 
 
I2.R=  (\frac{V}{R+r})^{2} . R