1. find total current ?
2. Current through each resistance ?
3. Potential difference on each resistance ?
Answers
Given :
- V = 2 v
- Resistors are of 2Ω, 4Ω and 8Ω.
To find :
- Total current.
- Current through each resistance.
- Potential difference on each resistor.
Solution :
Total resistance = ?
=> 1/R = 1/4 + 1/8 (In parallel)
=> 1/R = 3/8
=> R = 8/3.
Total resistance in circuit,
=> 2 Ω + 8/3 Ω
=> 14/3 Ω
a) Total current.
=> Current, I = V/R
=> I = 20/14/3
=> 20 × 3/14
=> I = 60/14 Ampere.
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b) Current through each resistor.
i) Through 2 Ω
=> In series, current passing through each resistor is equal (equal to net current flow).
Here net current flow is 60/14 A hence current passing through 2 Ω will be 60/14 A.
ii) Through 4 Ω
=> I = V/R
=> 11.43/4
=> 2.85
iii) Through 8 Ω
=> I = V/R
=> 11.43/8
=> 1.428
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c) Potential difference in each resistance.
i) Potential difference in 2 Ω.
=> Potential across 2Ω = I × R
=> V = 60/14 × 2
=> 60/7
=> 8.57 V
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Potential difference across parallel combination will be 20 - 8.57 = 11.43 V.
In parallel potential difference, it remains same across each resistor.
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ii) Potential difference across 4 Ω
=> Potential difference across 4V = potential difference across 8V = 11.43 V.
=> Current through 4Ω resistor will be
V/R = 11.43/4 = 2.85
iii) Potential difference across 8
=> Potential difference across 4V = potential difference across 8V = 11.43 V.
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