Advertisements
Advertisements
Question
A source of potential difference V volt sends current I ampere in a circuit for time t second. Write expressions for
- electrical energy supplied by the source and
- electrical power spent by the source.
Solution
Potential difference V is the work done in moving a unit charge
∴ Work was done in moving a charge Q through the pot. diff. V = QV
i.e. W = QV
but = `"Q"/"t" = "I"` or Q = It
∴ W = VIt
Work done = Electrical energy
(a) ∴ Electrical energy = VIt is the expression
(b) Power is the rate of doing W
P = `"W"/"t" = "VIt"/"t" = "VI"`
P = VI is the expression.
APPEARS IN
RELATED QUESTIONS
At what voltage is this current available to our household?
A switch should not be touched with wet hands.
Name the device used to protect the electric circuits from over loading and short circuit. On what effect of current does it work?
Write the full form of M.C.B?
What precaution do you observe while connecting a plug top into a socket?
Name two precautions to be observed while using an immersion heater.
List the safety features while handling electricity
Thomas Alva Edison invented more than ______ useful inventions which are used in homes.
What are the safety measures to safeguard a person from electric shock?
The resistance of a dry human body is high.
