Advertisements
Advertisements
प्रश्न
When an electric lamp is connected to 12 V battery, it draws a current of 0.5 A. The power of the lamp is:
(a) 0.5 W
(b) 6 W
(c) 12 W
(d) 24 W
Advertisements
उत्तर
6 W
Power, P = VI = 12 V x 0.5 A = 6 W
APPEARS IN
संबंधित प्रश्न
Define Electric power.
Which one has a higher electrical resistance : a 100 watt bulb or a 60 watt bulb?
An electric lamp is labelled 12 V, 36 W. This indicates that it should be used with a 1 V supply. What other information does the label provide?
Which uses more energy: a 250 W TV set in 1 hour or a 1200 W toaster in 10 minutes?
Calculate the cost of operating a heater of 500 W for 20 hours at the rate of Rs 3.90 per unit.
The commercial unit of energy is :
(a) watt
(b) watt-hour
(c) kilowatt-hour
(d) kilo-joule
At a given time, a house is supplied with 100 A at 220 V. How many 75 W, 220 V light bulb could be switched on in the house at the same time (if they are all connected in parallel)?
An electric heater of resistance 8 Ω takes a current of 15 A from the mains supply line. Calculate the rate at which heat is developed in the heater.
Write an expression for the electrical power spent in flow of current through a conductor in terms of
(a) Resistance and potential difference, (b) current and resistance.
Write the SI units for:
(a) Electric current
(b) Potential difference
(c) Charge.
The diagram shows a coil connected to a center zero galvanometerG . The galvanometer shows a deflect ion to the right when the north pole N of a powerful magnet is moved to the right as shown .

(i) Explain, why the defelct ion occurs in the galvanometer.
(ii ) State whether th e current in the coil is cl ockwise or anticl ockwise
when viewed from the end P.
(iii ) State th e observation in G when the coil is moved away from north
pole N of the magnet keeping the magnet stationary.
(iv)State the observation in G when both the coil and the magnet are
moved to right at th e same speed .
What is the energy conversion when an electric current passes through a metallic wire?
Name two common material used for heating elements.
Two lamps are rated 220V, 50W and the other rated 220V, 100W are connected in series with the mains of 220 V. Explain, why the 50W lamp glows more?
Give two precautious that you would take while putting off an electric switch.
Three 250 W heaters are connected in parallel to a 100 V supply, Calculate the energy supply in kWh to the three heaters in 5 hour.
An Electric bulb is marked 100 W, 230 V. What current does it take?
Out of the three fuses with current ratings 5A, 10A, 15A, which one is to be connected in a geyser circuit marked 3 kW, 220V? Give reason for your answer.
In the given figure, the emf of the cell is 2.2 V, and if internal resistance is 0.6 Ω. Calculate the power dissipated in the whole circuit.

1 kWh = ______ J.
