If the electric current in a lamp decreases by 5%, then the power output decreases by:
20%
10%
2.5%
5%
A
20%
B
5%
C
2.5%
D
10%
Open in App
Solution
Verified by Toppr
Let the original current be I and the resistance of the lamp be R
Then, power is P=I2R..........(i)
Reduced current value is 95% of original current value.
I′=0.95I
New power is:
P′=I′2R
P′=0.952I2R
P′=0.9025I2R
P′≈0.9R
Was this answer helpful?
12
Similar Questions
Q1
If the electric current in a lamp decreases by 5%, then the power output decreases by:
View Solution
Q2
The current through a lamp decreases by 1% The percentage change power of the lamp is
View Solution
Q3
If the current in an electric bulb decreases by 0.5%, the power in the bulb decreases by approximately
View Solution
Q4
If current in an electric bulb drops by one percent.Then the power decreases by
View Solution
Q5
Assertion : If the current of a lamp decreases by 20%, the percentage decrease in the illumination of the lamp is 40%. Reason : Illumination of the lamp is directly proportional to square of the current through lamp.