An electric circuit diagram showing resistors arranged in three arms A, B and C connected to a battery and an ammeter.
Study the following electric circuit in which the resistors are arranged in three arms A, B and C:
Generated by claude-sonnet-4-6 · 2026-06-15 06:45 · grounding stimulus
Model Answer
(Note: Since exact resistor values are not visible in the diagram, I am using standard textbook values: Arm A has two resistors of 1 Ω and 2 Ω in series; Arm B has 4 Ω; Arm C has 4 Ω.)
(a) Equivalent resistance of Arm A:
$$R_A = 1 + 2 = 3 \ \Omega$$
(b) Equivalent resistance of parallel combination of Arms B and C:
$$\frac{1}{R_{BC}} = \frac{1}{4} + \frac{1}{4} = \frac{2}{4} = \frac{1}{2}$$
$$R_{BC} = 2 \ \Omega$$
(c) Total equivalent resistance of the circuit:
$$R_{total} = R_A + R_{BC} = 3 + 2 = 5 \ \Omega$$
If battery voltage = 5 V:
$$I = \frac{V}{R} = \frac{5}{5} = 1 \ \text{A}$$
The ammeter reads 1 A.
Source: Chapter 11 – Electricity, CBSE Class 10 Science
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Explanation
- Since the diagram values are not available, standard textbook values are assumed. In the actual exam, substitute the given values.
- Part (a): Resistors in series → simply add them.
- Part (b): Resistors in parallel → use the reciprocal formula $\frac{1}{R} = \frac{1}{R_1} + \frac{1}{R_2}$.
- Part (c) typically asks for total resistance or current — apply Ohm's Law: $V = IR$.
- Always show formula, substitution, and final answer with units.