Question

Two fans rated (60w 220v) & (60w, 110v). Calculate their resistance and current passing in bulbs.

• A. R_{1 :} R₂ = 1 : 3 and i₁ : i₂ = 1 : 2
• B. R_{1 :} R₂ = 4 : 1 and i₁ : i₂ = 1 : 2​
• C. R_{1 :} R₂ = 1 : 2 and i₁ : i₂ = 4 : 1​
• D. Information is insufficient

Answer 1

The correct option is B

R_{1 :} R₂ = 4 : 1 and i₁ : i₂ = 1 : 2​

P = $\frac{V^2}{R}$

Hence, R₁ : R₂ = 4 : 1

Also P = V*I

Hence, i₁ : i₂ = 1 : 2