Current Electricity, Charging & Discharging Of Capacitors / वर्तमान बिजली, चार्ज और कैपेसिटर का निर
JEE Main & Advanced
Physics
Current Electricity, Charging & Discharging Of Capacitors / वर्तमान बिजली, चार्ज और कैपेसिटर का निर
Question Bank
Grouping of Resistances
question_answer
In circuit shown below, the resistances are given in ohms and the battery is assumed ideal with emf equal to 3 volt. The voltage across the resistance R4 is [UPSEAT 2004; Kerala PMT 2004]
A) 0.4 V
B) 0.6 V
C) 1.2 V
D) 1.5 V
Correct Answer:
A
Solution :
Equivalent resistance of the given network \[{{R}_{eq}}=75\,\Omega \] \ Total current through battery \[i=\frac{3}{75}\] \[{{i}_{1}}={{i}_{2}}=\frac{3}{75\times 2}=\frac{3}{150}\] Current through \[{{R}_{4}}=\frac{3}{150}\times \frac{60}{(30+60)}\]\[=\frac{3}{150}\times \frac{60}{90}=\frac{2}{150}A\] \[{{V}_{4}}={{i}_{4}}\times {{R}_{4}}=\frac{2}{150}\times 30=\frac{2}{5}V=0.4\,V\]