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?




  1. Class 10
  2. Chapter 12 Class 10 - Electricity


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.

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo