© examsnet.com
Question : 13
Total: 15
An electric motor rated 1100 W is connected to 220 V mains. Find:
(i) The current drawn from the mains,
(ii) Electric energy consumed if the motor is used for5 hours daily for 6 days.
(iii) Total cost of energy consumed if the rate of one unit is₹ 5 .
OR
Study the following circuit and find :
(ii) Current drawn from the battery
(iii) Potential difference across the5 Ω resistor
(i) The current drawn from the mains,
(ii) Electric energy consumed if the motor is used for
(iii) Total cost of energy consumed if the rate of one unit is
OR
Study the following circuit and find :
(i) Effective resistance of the circuit
(ii) Current drawn from the battery
(iii) Potential difference across the
Solution:
(i) Effective resistance of the circuit
R 3 and R 4 are in series and both are parallel to R 2
R 3 + R 4 = 10 Ohm
Effective Resistance acrossR 2 ( R ′ )
1 ∕ R ′ = 1 ∕ R 2 + 1 ∕ ( R 3 + R 4 )
R ′ = 5 Ohm
Now,R 1 , R ′ and R 5 are in series
Effective resistance of the circuit= R 1 + R ′ + R 5
= 5 + 5 + 10
= 20 Ohm
(ii) Current drawn from battery
V = I R
I = V ∕ R
I = 20 ∕ 20
I = 1 A
(iii) Potential difference across 5-ohm resistor
V = I R
V = 1 × 5
V = 5 V
Effective Resistance across
Now,
Effective resistance of the circuit
(ii) Current drawn from battery
(iii) Potential difference across 5-ohm resistor
© examsnet.com
Go to Question: