Let the resistance of an electrical component remains constant while the potential difference across the two ends of the component decreases to half of its former value. What change will occur in the current through it?

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Transcript

Case 1 Resistance = R Potential Difference = V Case 2 Resistance = R Potential Difference = 𝑉/2 By Ohm’s law, V = I R 𝑉/𝑅 = I ∴ I = 𝑉/𝑅 Current in Case 1 I1 = 𝑉/𝑅 Current in Case 2 I2 = 𝑉/2 Γ— 1/𝑅 = 𝑉/2𝑅 Now, 𝐼_1/𝐼_2 = (𝑉/𝑅)/(𝑉/2𝑅) 𝐼_1/𝐼_2 = 𝑉/𝑅 Γ— 2𝑅/𝑉 𝐼_1/𝐼_2 = 2 1/2 𝐼_1 = 𝐼_2 𝐼_2 = 1/2 𝐼_1 ∴ When voltage becomes half, current also becomes half.

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CA Maninder Singh is a Chartered Accountant for the past 14 years and a teacher from the past 18 years. He teaches Science, Economics, Accounting and English at Teachoo