Advertisements
Advertisements
प्रश्न
Unit of electric power may also be expressed as
विकल्प
volt ampere
kilowatt hour
watt second
joule second
Advertisements
उत्तर
volt ampere
Explanation -
Power is defined as
P = VI
where, V = Potential difference (Volt)
I = Current (Ampere)
So, unit of electric power may also be expressed as volt ampere.
APPEARS IN
संबंधित प्रश्न
Why are metals good conductors of electricity whereas glass is a bad conductor of electricity? Give reason?
The work done in moving a unit charge across two points in an electric circuit is a measure of:
(a) current
(b) potential difference
(c) resistance
(d) power
How many milliamperes as there in 1 ampere?
Write down the formula which relates electric charge, time and electric current
The circuit diagram given below shows the combination of three resistors R1, R2 and R3:
Find :
(i) total resistance of the circuit.
(ii) total current flowing in the circuit.
(iii) the potential difference across R1.
Match the pairs.
| ‘A’ Group | ‘B’ Group |
| 1. Free electrons | a. V/R |
| 2. Current | b. Increases the resistance in the circuit |
| 3. Resistivity | c. Weakly attached |
| 4. Resistances in series | d. VA/LI |
Tick(✓) the correct choice in the following:
24 watt, 12 volt head lamp is fully lit by connecting it to a 12 volt
battery. The working resistance of the lamp is
Define the following:
Super conductors
Find the effective resistance in the following circuit diagrams (Fig.):

Electrical power P is given by the expression P = (Q × V) ÷ time
(a) What do the symbols Q and V represent?
(b) Express the power P in terms of current and resistance explaining the meanings of symbols used there in.
Complete the following:
1 kWh = _________ J
An electric bulb is rated 250 W, 230 V.
- the energy consumed in one hour, and
- the time in which the bulb will consume 1.0 kWh energy when connected to 230 V mains.
My mother was operating washing machine on Sunday morning. Suddenly, she saw a spark coming out of the electric board and the electric current in the house failed. An electrician was called to look into the matter. What should he have noticed.
State the condition when it is advantageous to connect cells in series.
Conventionally, the direction of the current is taken as:
Match the items in column-I to the items in column-II:
| Column - I | Column - II |
| (i) electric current | (a) volt |
| (ii) potential difference | (b) ohm meter |
| (iii) specific resistance | (c) watt |
| (iv) Electrical power | (d) joule |
| (v) electrical energy | (e) ampere |
