Advertisements
Advertisements
Question
The SI unit of energy is :
(a) joule
(b) coulomb
(c) watt
(d) ohm-metre
Advertisements
Solution
(a) joule
Joule is the SI unit of energy.
APPEARS IN
RELATED QUESTIONS
Which uses more energy, a 250 W TV set in 1 hr, or a 1200 W toaster in 10 minutes?
1kWh = …….. J
An electric bulb is rated ‘100 W, 250 V’. What information does this convey?
Two bulbs are rated 60 W, 220 V and 60 W, 110 V respectively. Calculate the ratio of their
resistances
A battery of e.m.f 15 V and internal resistance 2 Ω is connected to two resistors of resistance 4 ohm and 6 ohm joined in series. Find the electrical energy spent per minute in 6 ohm resistor.
The diagram below shows a magnetic kept just below the conductor AB which is kept in North South direction.

(i) In which direction will the needle deflect when the key is closed ?
(ii) Why is the deflection produced ?
(iii) What will be the change in the deflection if the magnetic needle is taken just above the conductor AB ?
(iv) Name one device which works on this principle.
Tick(✓) the correct choice in the following:
In the circuit shown in the following fig, the e.m.f. of the cell is 4 volts, the current
flowing through the resistor is

An electric iron rated 750 W is operated for 2 hours/day. How much energy is consumed by the electric iron for 30 days?
Define Kilo watt hour.
Why does not the heating coil produce any visible light? in an electric stove.
What is ‘Rating’ of an electric appliance?
Give two precautious that you would take while putting off an electric switch.
Why is the electric power from the generating station transmitted at high voltage?
An electric heater is rated 220 V, 550 W. Electrical energy is also measured in kWh. What do you understand by a kilo-watt-hour?
Unit of electric power may also be expressed as:
The unit of e.m.f. of a cell is ____________.
A fuse is rated 5 A. Can it be used with a geyser rated 1540 W, 220 V Write Yes or No. Give supporting calculations to justify your answer.
