Advertisements
Advertisements
Question
Unit of electric power may also be expressed as
Options
volt ampere
kilowatt hour
watt second
joule second
Advertisements
Solution
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
RELATED QUESTIONS
One coulomb charge is equivalent to the charge contained in:
(a) 2.6 × 1019 electrons
(b) 6.2 × 1019 electrons
(c) 2.65 × 1018 electrons
(d) 6.25 × 1018 electrons
Which of the following equation shows the correct relationship between electrical unit?
1A = 1C/s or 1c= 1A/s
What is an Ammeter? How is It Connected in a Circuit? Draw a Diagram to Illustrate Your Answer.
Three resistors are connected as shown in the diagram.
Through the resistor 5 ohm, a current of 1 ampere is flowing.
(i) What is the current through the other two resistors?
(ii) What is the p.d. across AB and across AC?
(iii) What is the total resistance
Ten bulbs are connected in a series circuit to a power supply line. Ten identical bulbs are connected in a parallel circuit to an identical power supply line.
(d) Which circuit would have less current in it?
For a heater rated at 4 kW and 220 V, calculate:
(a) the current,
(b) the resistance of the heater,
(c) the energy consumed in 2 hours, and
(d) the cost if 1 kWh is priced at Rs 4.60.
A wire of uniform thickness with a resistance of 27Ω is cut into three equal pieces and they are joined in parallel. Find the equivalent resistance of the parallel combination.
A wire of length 5 m has a resistance of 2.0 Ω calculate:
(a) the resistance of wire of length 1 m
(b) the equivalent resistance if two such wires each of length 2 m are joined in parallel.
(c) the resistance of 1 m length of wire of same material but of half diameter.
If a charge of 420 C flows through a conducting wire in 5 minutes what is the value of the current?
Complete the following sentence:
A fuse is connected in ........... with the ......... wire.
Find the effective resistance in the following circuit diagrams (Fig.):

A wire is passed through a piece of cardboard as shown in fig .. An electric current flows vertically down the wire and then flows back up. The two sections of the write are observed to repel each other.
(a) Wi th the aid of a diagram, describe how you would plot the magnetic field lines on the card .

(b) Sketch the magnetic field patterns around both the sections of the wire. Use your sketch to explain why the two sections repel each other.
(c) The repulsive force between the two sections is small. What changes could be made to increase it?
Three heaters each rated 250 W, 100 V are connected in parallel to a 100 V supply. Calculate :
The total current taken from the supply
Three heaters each rated 250 W, 100 V are connected in parallel to a 100 V supply. The resistance of each heater
An electric kettle is rated 2.5 kW, 250 V. Find the cost of running the kettle for two hours at Rs. 5.40 per unit.
What should I choose ___________________
b. for getting protection from electric current.
c. to measure the current in the circuit?
What does the direction of current convey?
