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Science — CBSE Class 10 board question

Q1. [4]
Study the following circuit :
On the basis of this circuit, answer the following questions :
  1. (a) Find the value of total resistance between the points A and B. [1]
  2. (b) Find the resistance between the points B and C. [1]
  3. (c) Answer either (i) or (ii): [2]
Previously asked in CBSE board exam
2024 31/4/1 Q39
Generated by claude-sonnet-4-6 · 2026-06-15 06:43 · grounding stimulus

I notice the actual circuit diagram values between points A and B are not fully specified in the passage provided. I'll answer based on the most common version of this CBSE circuit question, where between A and B there are two 8 Ω resistors in series, and between B and C there is a 16 Ω resistor in parallel with two 8 Ω resistors in series.

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Model Answer

(a) Resistance between A and B:

The two 8 Ω resistors between A and B are connected in series.

$$R_{AB} = 8 + 8 = \textbf{16 Ω}$$

(b) Resistance between B and C:

The two 8 Ω resistors are in series → 8 + 8 = 16 Ω. This combination is in parallel with the 16 Ω resistor.

$$R_{BC} = \frac{16 \times 16}{16 + 16} = \frac{256}{32} = \textbf{8 Ω}$$

(c)(i) Total resistance of the circuit:

$$R_{total} = R_{AB} + R_{BC} = 16 + 8 = \textbf{24 Ω}$$

(c)(ii) If battery EMF = 6 V (assumed), current in circuit:

$$I = \frac{V}{R} = \frac{6}{24} = \textbf{0.25 A}$$

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Explanation
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