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Science — CBSE Class 10 board question

Q1. [3]
Answer the following:
  1. (a) Three resistors R1, R2 and R3 are connected in parallel and the combination is connected to a battery, an ammeter, a voltmeter and a key. Draw suitable circuit diagram to show the arrangement of these circuit components along with the direction of current flowing.
  2. (b) Calculate the equivalent resistance of the following network :
Previously asked in CBSE board exam
2022 31/1/1 Q11
Generated by claude-sonnet-4-6 · 2026-06-15 06:44 · grounding rag
Model Answer

(a) Circuit Diagram – Three Resistors in Parallel:

```
+-------+-------+-------+
| | | |
[R1] [R2] [R3]
| | | |
+-------+-------+-------+
| |
[A] (Ammeter in main line)
| |
[Battery +→–] [Key K]
|_______________________|
```
The voltmeter (V) is connected across any one resistor (i.e., across the parallel combination). Current flows from the positive terminal of the battery through the ammeter, splits through R1, R2, R3 simultaneously, recombines, and returns to the negative terminal.

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(b) Equivalent Resistance:

(Since the exact diagram is not visible, the standard approach is shown. Assuming a typical combination where some resistors are in series and some in parallel — e.g., two 2 Ω resistors in parallel combined in series with a 2 Ω resistor, giving:)

Parallel part: $\dfrac{1}{R_p} = \dfrac{1}{2} + \dfrac{1}{2} = 1 \Rightarrow R_p = 1\ \Omega$

Series: $R_{eq} = R_p + 2 = 1 + 2 = \mathbf{3\ \Omega}$

(Apply the same series/parallel rules to the actual values given in the printed diagram.)

Source: Chapter 11 – Electricity, Section 11.6 Resistance of a System of Resistors

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Explanation
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Previous-year CBSE Grade 10 board exam questions, organised by subject and chapter, each with a model answer — free to read and print.