Published by:
CGP EDU Academic Team
Published on: September 12, 2026
Find the potential difference between the points A and B and between the points B and C of figure in steady state.

Text Solution
Verified by ExpertsThe correct answer is:
B
Step 1: Analyze the circuit. We have a series-parallel circuit with capacitors and resistors.
Step 2: Calculate the equivalent capacitance for the capacitors connected to the battery (C1 = 3 µF and C2 = 3 µF in parallel):
$$ C_{eq1} = C1 + C2 = 3 + 3 = 6 \mu F $$
Step 3: The 1 µF capacitors are in series with the equivalent capacitance calculated from the previous step. The formula for capacitors in series is:
$$ \frac{1}{C_{eq2}} = \frac{1}{C_{eq1}} + \frac{1}{1} $$
Therefore,
$$ C_{eq2} = \frac{6 \cdot 1}{6 + 1} = \frac{6}{7} \mu F $$
Step 4: Now calculate the voltage across the equivalent capacitor and the resistors using the voltage divider rule:
The total resistance is 50 Ohms (30Ω + 20Ω). The voltage across the resistors can be calculated as follows:
$$ V_{AC} = 100 \cdot \frac{20}{30 + 20} = 100 \cdot \frac{20}{50} = 40 V $$
Step 5: The potential difference between points A and B is 40 V.
Step 6: Calculate the potential difference between B and C: The voltage drop across the second branch (1 µF) can be calculated because the voltage across the components is the same, leading us to conclude that the potential difference between B and C is 60 V.
Therefore, the answers are 40V (A to B) and 60V (B to C). Thus, the correct answer option is B.
Step 2: Calculate the equivalent capacitance for the capacitors connected to the battery (C1 = 3 µF and C2 = 3 µF in parallel):
$$ C_{eq1} = C1 + C2 = 3 + 3 = 6 \mu F $$
Step 3: The 1 µF capacitors are in series with the equivalent capacitance calculated from the previous step. The formula for capacitors in series is:
$$ \frac{1}{C_{eq2}} = \frac{1}{C_{eq1}} + \frac{1}{1} $$
Therefore,
$$ C_{eq2} = \frac{6 \cdot 1}{6 + 1} = \frac{6}{7} \mu F $$
Step 4: Now calculate the voltage across the equivalent capacitor and the resistors using the voltage divider rule:
The total resistance is 50 Ohms (30Ω + 20Ω). The voltage across the resistors can be calculated as follows:
$$ V_{AC} = 100 \cdot \frac{20}{30 + 20} = 100 \cdot \frac{20}{50} = 40 V $$
Step 5: The potential difference between points A and B is 40 V.
Step 6: Calculate the potential difference between B and C: The voltage drop across the second branch (1 µF) can be calculated because the voltage across the components is the same, leading us to conclude that the potential difference between B and C is 60 V.
Therefore, the answers are 40V (A to B) and 60V (B to C). Thus, the correct answer option is B.
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems
The capacity of a parallel plate condenser is . When a glass plate is placed between the plates of…
A capacitor is charged by using a battery which is then disconnected. A dielectric slab is then sli…
The energy of a charged capacitor is given by the expression ( $\alpha$ = charge on the conductor a…
The capacity of a condenser is $4 \times 10^{-6}$ farad and its potential is 100 volts . The energy…
The insulated spheres of radii $R_1$ and $R_2$ having charges $Q_1$ and $Q_2$ respectively are conn…
In a charged capacitor, the energy resides