Advertisements
Advertisements
प्रश्न
Which of the following terms does not represent electrical power in a circuit?
विकल्प
I2R
IR2
VI
`"V"^2/"R"`
Advertisements
उत्तर
IR2
Explanation:
Electrical power is given by the expression P = VI ....(i)
According to Ohm’s law,
V = IR
Substituting the value of V in (i), we get
P = (IR) × I
P = I2R
Similar, to Ohm’s law,
I = `"V"/"R"`
Substituting the value of I in (i), we get
P = `"V" xx "V"/"R" = "V"^2/"R"`
From this, it is clear that the equation IR2 does not represent electrical power in a circuit.
संबंधित प्रश्न
The diagram below shows a circuit containing a lamp L, a voltmeter and an ammeter,. The voltmeter reading 3 V and the ammeter reading is 0.5 A.
What is the resistance of the lamp?
What is the power of the lamp?
Which of the following is the most likely temperature of the filament of an electric light bulb when it is working on the normal 220 V supply line?
(a) 500°C
(b) 1500°C
(c) 2500°C
(d) 4500°C
Electrical power p is given by the expression P = (Q × V) ÷ time. Express the power P in terms of current and resistance explaining the meaning of symbols used there in.
1kWh = …….. J
State the S.I. units of electrical power and electrical energy.
(i) Define the household unit of electricity.
(ii) What is the voltage of the electricity that is generally supplied to a house?
State the position of heating element with respect to principal focus of concave reflector and give reason for choosing this position.
Why is the heating element of an electric oven wound on a helix? State the reason.
State two advantages of filling an inert gas in an evacuated electric filament lamp.
If the rating of an electric bulb is 100W – 230V, Explain its meaning.
What is the order of current drawn by appliances connected to the ‘power circuit’ of a household?
An electric bulb is rated 240V-60W and is working at 100% efficiency.
(i) Calculate the resistance of bulb.
(ii) (a) Draw the circuit diagram.
(b) What is the rate of conversion of energy in each bulb?
(c) Total power used by the bulbs.
How can electric energy consumed by an electric appliance be calculated in kilowatt hour (kWh)?
An Electric bulb is marked 100 W, 230 V. What find the energy consumed by the bulb in one hour.
An Electric bulb is marked 100 W, 230 V. What how long would this lamp take to consume one unit of electricity?
A bulb is connected to a battery of e.m.f. 6V and internal resistance 2Ω A steady current of 0.5A flows through the bulb. Calculate the heat energy dissipated in the bulb in 10 minutes.
A cooler of 1500 W, 200 volts and a fan of 500 W, 200 volts are to be used from a household supply. The rating of fuse to be used is:
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.
Two heaters A and B have power rating of 1 kW and 2 kW, respectively. Those two are first connected in series and then in parallel to a fixed power source. The ratio of power outputs for these two cases is ______
