Question

a lamp rated 200w at 220v is connected to main electric supply (a) what amount of current is drawn from supply line if voltage is 220v?what is it resistance?
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Answer 1

Answer

• Current drawn will be 0.9 A
• Resistance will be 242Ω

Explanation

Given

• Power = 220 W
• Potential Difference = 220 V

To Find

• Current Drawn from the supply line of 220V
• Resistance of the circuit

Solution

● The current in the circuit can be found with the help of the formula P = VI

● Resistance can be found with the help of P = V²/R

✭ Current In the ciricuit

→ P = VI

→ 200 = 220 × I

→ 200/220 = I

→ 20/22 = I

→ Current = 0.9 A

✭ Resistance In the ciricuit

→ P = V²/R

→ 200 = 220²/R

→ 200 = 48400/R

→ 200 × R = 48400

→ R = 48400/200

→ Resistance = 242Ω

Answer 2

GIVEN :–

• Power (p) = 220 w

• Potential difference = 220 v

TO FIND :–

• Resistance of the circuit

• Current drawn from the supply line of 220 V

SOLUTION :–

♣Using formula :—

• P = V1

⟹ 200 = 220 × I

⟹ 200/220 = I

⟹ I = 200/220

⟹ I = 20/22

⟹ Current = 0.9

____________________________

♣Using formula :—

• P = V²/R

⟹ 200 = 220²/R

⟹ 200 = 48400/R

⟹ R = 48400/200

⟹ Resistance = 242

____________________________

ANSWERS :–

• Current drawn = 0.9 A

• Resistance = 242 Ω