Question

A cell of negligible resistance and emf $2$ volt is connected to a series combination of $2,3$ and $5$ ohm. The potential difference in volts between the terminals of $3$-ohm resistance will be:

• A. $0.6volt$
• B. $\frac{2}{3}volt$
• C. $3volts$
• D. $6volts$

Answer 1

Answer: (A)

$0.6volt$

In a serially connected circuit the voltage across is directly proportional to the resistance in the circuit. That is, $V\propto R$.
So, $\frac{V}{V_{total}}=\frac{R}{R_{total}}$
The total resistance $R$ in the circuit is $R=2+3+5=10$ ohm.
Since, the resistance of the $3$ ohms resistor is only three tenth of the total resistance, the applied voltage is given as $\frac{3}{10}\times 2=0.6$ volt
Hence, the potential difference between the terminals of 3 ohm resistance will be 0.6 volt.