Advertisements
Advertisements
प्रश्न
How can electric energy consumed by an electric appliance be calculated in kilowatt hour (kWh)?
Advertisements
उत्तर
The electric energy in kWh van be calculated as follows:
Energy in kWh = `("Power" ("in watt") xx "Time"("in hour"))/1000`
or kWh = `("V"("volt") xx "i" ("ampere") xx "t" ("hour"))/1000`
∴ Energy (in kWh) = `"Vit"/1000`
संबंधित प्रश्न
An electric lamp is labelled 12 V, 36 W. This indicates that it should be used with a 12 V supply. What other information does the label provide?
Define watt. Write down an equation linking watts, volts and amperes.
List the names of three electrical gadgets used in your house. Write their power, voltage rating and approximate time for which each one is used in a day. Hence, find the electrical energy consumed by each in a day.
What is the resistance, under normal working conditions of a 240 V electric lamp rated at 60 W? If two such lamps are connected in series across a 240 V mains supply, explain why each one appears less bright.
An electric toaster draws 8 A current in a 220 V circuit. It is used for 2 h. Find the cost of
operating the toaster if the cost of electrical energy is Rs. 4.50 per kWh.
What is the function of the split rings in a d.c. motor?
With reference to the diagram shown below calculate:

(i) The equivalent resistance between P and Q.
(ii) The reading of ammeter.
(iii) The electrical power between P and Q.
What is the resistance of an appliance rated at V volt, P watt?
A student wants to use an electric heater, an electric bulb and an electric fan simultaneously.
How should these gadgets be connected with the mains? Justify your answer giving three reasons.
