Unit of electric power may also be expressed as
(a) volt ampere
(b) kilowatt hour
(c) watt second
(d) joule second
NCERT Class X
Science - Exemplar Problems
Chapter_Electricity
Answers
Answer: Unit of electric power may also be expressed as (i) Volt Ampere
Explanation:
(i) Volt Ampere is the unit of apparent power in an electric circuit where apparent power is the product of root mean square voltage and root mean square current.
(ii) Kilowatt hour is the unit of energy which is equal to 1 kilowatt power which is sustainable for an hour.
(iii) Watt second is the unit of energy which is equal to 1 watt power which is sustainable for a second.
(iv) Joule second is the unit of having use kn Planck's constant.
Answer:
Volt Ampere
Explanation:
When a current flows through a resistor, electrical energy is converted into heat energy. The heat generated in the components of a circuit, all of which possess at least some resistance, is dissipated into the air around the components. The rate at which the heat is dissipated is called power, and is measured in units of watts (W).
To find the power (P) using V and I, we use P=VI. Here, the unit of Voltage (V) is volt and Current (I) is ampere.
Hence, the unit of electric power can also be expressed as volt ampere.