Current Electricity

JEE Main level, single correct, medium

206 of 380

Question 206 of 380

The voltage and the current between AA and BB points shown in the circuit are _____.

Show answer and solution

Answer: (B) 2424 V, 44 A

The four parallel branches between the common left node AA and the common right node are all identical: each consists of a 27 V27\text{ V} source in series with a 3 Ω3\ \Omega resistor. In the third branch, the two cells (14 V(14\text{ V} and 13 V)13\text{ V}) aid each other, giving a net EMF of 14+13=27 V14 + 13 = 27\text{ V}.

Thevenin equivalent between AA and BB:
Since all four branches have the same EMF and polarity in parallel:
Vth=27 VV_{th} = 27\text{ V}

The four 3 Ω3\ \Omega resistors in parallel give:
Rth=34=0.75 ΩR_{th} = \dfrac{3}{4} = 0.75\ \Omega

Load branch (diagonal):
The diagonal connecting AA and BB consists of two 3 Ω3\ \Omega resistors in series, so:
RL=3+3=6 ΩR_L = 3 + 3 = 6\ \Omega

Current through the diagonal branch:
I=VthRth+RL=270.75+6=276.75=4 AI = \dfrac{V_{th}}{R_{th} + R_L} = \dfrac{27}{0.75 + 6} = \dfrac{27}{6.75} = 4\text{ A}

Voltage across AA and BB:
VAB=I⋅RL=4×6=24 VV_{AB} = I \cdot R_L = 4 \times 6 = 24\text{ V}

Hence, the voltage is 24 V24\text{ V} and the current is 4 A4\text{ A}, which corresponds to option (2) 24 V, 4 A(2)\ 24\text{ V},\ 4\text{ A}.

JEE Main question paper PDF

Open a shift to read the full paper on this page, or download it.

JEE Main 2025 Apr 2 Shift 1 question paper

Open Download PDF

Opening paper…

Explain it as a whiteboard videoStep-by-step, in Hinglish or English. Your first video needs no login.Solved it on paper but got it wrong?Upload a photo of your working. Mistake Doctor marks the exact line that broke.
See it move: Circuit builder simulationDrag the sliders and watch the numbers in this question change.Revise Current Electricity firstFormula sheet, solved examples and the traps students fall into.

More Physics practice

JEE Main Physics practice question on Current Electricity (Kirchoffs Laws), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.