find equivalent resistance
Answers
Answer:
The required equivalent resistance is 3 Ω
Explanation:
To know :
- When resistors of resistances R₁ , R₂ , R₃ .... are connected in series, the equivalent resistance is given by
R = R₁ + R₂ + R₃ + ...
- When resistors of resistances R₁ , R₂ , R₃ .... are connected in parallel, the equivalent resistance is given by
1/R = 1/R₁ + 1/R₂ + 1/R₃ + ...
Solution :
[Refer to the attachment]
R₁ = R₂ = R₃ = 4
R₄ = 12
R₅ = 3
R₆ = R₇ = 0.5
R₁, R₂, R₃ are connected in series. Let R₁₂₃ be it's equivalent resistance.
R₁₂₃ = R₁ + R₂ + R₃
R₁₂₃ = 4 + 4 + 4
R₁₂₃ = 12
R₁₂₃, R₄, R₅ are connected in parallel combination. Let R₁₂₃₄₅ be it's equivalent resistance.
1/R₁₂₃₄₅ = 1/R₁₂₃ + 1/R₄ + 1/R₅
1/R₁₂₃₄₅ = 1/12 + 1/12 + 1/3
1/R₁₂₃₄₅ = (1+1)/12 + 1/3
1/R₁₂₃₄₅ = 2/12 + 1/3
1/R₁₂₃₄₅ = 1/6 + 1/3
1/R₁₂₃₄₅ = (1+2)/6
1/R₁₂₃₄₅ = 3/6
1/R₁₂₃₄₅ = 1/2
R₁₂₃₄₅ = 2
R₁₂₃₄₅, R₆, R₇ are connected in series. Let R₁₂₃₄₅₆₇ be the equivalent resistance.
R₁₂₃₄₅₆₇ = R₁₂₃₄₅ + R₆ + R₇
R₁₂₃₄₅₆₇ = 2 + 0.5 + 0.5
R₁₂₃₄₅₆₇ = 2 + 1
R₁₂₃₄₅₆₇ = 3
Therefore, the equivalent resistance is 3 Ω