Advertisements
Advertisements
Question
Give two reasons why nichrome alloy is used for making the heating elements of electrical appliances.
Advertisements
Solution
Nichrome is used to make the heating elements of electrical appliances because it has a high resistance and a high melting point.
APPEARS IN
RELATED QUESTIONS
Why does the cord of an electric heater not glow while the heating element does?
Why does the connecting cord of an electric heater not glow hot while the heating element does?
Write down the formula for the heat produced when a current I is passed through a resistor R for time t.
What is meant by the heating effect of current? Give two applications of the heating effect of current.
How does the wire in the filament of a light bulb behave differently to the other wires in the circuit when the current flows?
What property of the filament wire accounts for this difference?
Two exactly similar heating resistances are connected (i) in series, and (ii) in parallel, in two different circuits, one by one. If the same current is passed through both the combinations, is more heat obtained per minute when they are connected in series or when they are connected in parallel? Give reason for your answer.
What is the heating effect of electric current?
Which metal is used to make the filament of an electric bulb?
What is used to turn off the sudden increase in current in the electrical circuit of the house nowadays?
Name any two appliances which work under the principle of heating effect of current.
An electric iron draws a current of 4 A when connected to 220 V mains. Its resistance must be:
Three incandescent bulbs of 100 W each are connected in series in an electric circuit. In another circuit another set of three bulbs of the same wattage are connected in parallel to the same source.
- Will the bulb in the two circuits glow with the same brightness? Justify your answer.
- Now let one bulb in both the circuits get fused. Will the rest of the bulbs continue to glow in each circuit? Give reason.
Can we use the same fuse in a geyser and a television set? Explain.
Your teacher has shown you the following activity.

Activity: Teacher has wound a long insulated piece of wire around an iron nail in the form of a coil. Free ends of the wire are connected to a cell through a switch as shown in the following figure. The current is switched on and some pins are placed near the ends of the nail.
Write down any three questions that come to your mind about this activity.
What are the uses of electromagnets?
Fuse is a strip of alloy wire which is made up of lead and tin with a very low ______.
A fuse is used in an electric circuit to stop high currents flowing through the circuit.
The electric fuse works on the Joule heating principle.
Define the following:
Electrolyte
