Advertisements
Advertisements
प्रश्न
What determines the rate at which energy is delivered by a current?
उत्तर
The rate of consumption of electric energy in an electric appliance is called electric power. Hence, the rate at which energy is delivered by a current is the power of the appliance.
APPEARS IN
संबंधित प्रश्न
Which uses more energy, a 250 W TV set in 1 hr, or a 1200 W toaster in 10 minutes?
What is the SI unit of (i) electric energy, and (ii) electric power?
The SI unit of energy is :
(a) joule
(b) coulomb
(c) watt
(d) ohm-metre
State the S.I. unit of electrical power.
A current of 2 A is passed through a coil of resistance 75Ω for 2 minutes. (a) How much heat energy is produced? (b) How much charge is passed through the resistance?
Why is heating element wound on a long porcelain rod in a room heater.
State the position of heating element with respect to principal focus of concave reflector and give reason for choosing this position.
What changes in energy occur in an electric bulb?
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?
Of the three connecting wires in a household circuit: Which two of the three wires are at the same potential? In which of the three wires should the switch be connected?
Why is the electric power from the generating station transmitted at high voltage?
State the reason why, in a three pin plug, the earth pin is longer and thicker than the other two.
How does earthing prevent electrical shock?
State other bigger units of electric power and express them in watt.
An Electric bulb is marked 100 W, 230 V. What how long would this lamp take to consume one unit of electricity?
Two bulbs are rated: bulb A 100W, 120 V bulb B 10W, 120 V. If both are connected across a 120V supply, which bulb will consume more energy, When in series? Also calculate the current through each bulb in above cases.
Compare the power used in the 2 Ω resistor in each of the following circuits:
- a 6 V battery in series with 1 Ω and 2 Ω resistors
- a 4 V battery in parallel with 12 Ω and 2 Ω resistors.
Using a long extension cord in which each conductor has a resistance of 8Ω, a bulb marked as '100 W, 200 V' is connected to a 220 V dc supply of negligible internal resistance as shown in the figure. The power delivered to the bulb is ______ W.