Question

The current flowing through 3 ohm resistor is 0.8 ampere, the potential drop across the 4 ohm resistor is :

• A. 1.6 V
• B. 2.4V
• C. 4.8 V
• D. 9.6 V

Answer 1

The correct option is C 4.8 V

Given : $I_1=0.8$ A

Thus voltage drop across 3 ohm, $V_1=I{R}_1=0.8\times 3=2.4$ volts

As 3 ohm and 6 ohm are connected in parallel, thus voltage across them is equal.

$\therefore$ Current through 6 ohm, $I_2=\frac{V_1}{R_2}=\frac{2.4}{6}=0.4$ A

Current through 4 ohm resistor $I^{\prime }=I_1+I_2=0.8+0.4=1.2$ A

$\therefore$ Potential drop across 4 ohm, $V^{\prime }=I^{\prime }{R}_3=1.2\times 4=4.8$ volts