Two lamps, one rated 100 W at 220 V, and the other 60 W at 220 V, are connected in parallel to electric mains supply. What current is drawn from the line if the supply voltage is 220 V?

Slide58.JPG

Slide59.JPG
Slide60.JPG
Slide61.JPG

  1. Class 10
  2. Chapter 12 Class 10 - Electricity (Term 2)

Transcript

NCERT Question 15 Two lamps, one rated 100 W at 220 V, and the other 60 W at 220 V, are connected in parallel to electric mains supply. What current is drawn from the line if the supply voltage is 220 V? Given Potential difference = V = 220 V Power of lamp 1 = P1 = 100 W Power of lamp 2 = P2 = 60 W We need to find current through the circuit We know that In parallel combination current gets divided among the resistors But, Net current = Sum of current through individual resistors I = I1 + I2 Finding current We know that, Power = Voltage × Current P = V I ∴ I = 𝑃/𝑉 Lamp 1 I1 = 𝑃_1/𝑉 I1 = 100/220 I1 = 10/22 I1 = 5/11 A Lamp 2 I2 = 𝑃_2/𝑉 I2 = 60/220 I2 = 6/22 I2 = 3/11 A Net current I = I1 + I2 I = 5/11 + 3/11 I = 8/11 I = 0.73 A Net current through circuit is 0.73 A

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