Advertisements
Advertisements
Question
When current is switched ‘on’ in a room heater, it ______.
Solution
When current is switched ‘on’ in a room heater, it becomes red hot and emits heat.
Explanation:
The working of a room heater is based on the heating effect of electric current, which converts electrical energy into heat energy to warm the room.
APPEARS IN
RELATED QUESTIONS
State four most common electrical appliances based on heating effect of electric current. Why do we use finely heated platinum wire in surgery?
An electric heater is connected to the 230 V mains supply. A current of 8 A flows through the heater.
(b) How much energy is transferred to the heater each second?
Why is a series arrangement not used for connecting domestic electrical appliances in a circuit?
If the current flowing through a fixed resistor is halved, the heat produced in it will become:
(a) Observe the diagram given below and state whether the bulb will glow or not when we switch on K.
(b) Is it safe to handle the bulb when the switch is OFF?
(c) Give a reason for your answer in (b).
What is a trip switch?
Explain why fuse wire is always connected in a series arrangement.
In the electric equipment producing heat like iron, electric heater, boiler, toaster etc., an alloy such as nichrome is used, not pure metals.
In a set up the students coated iron nails with zinc metal and noted that, iron nails coated with zinc prevents rusting. They also observed that zinc initially acts as a physical barrier, but an extra advantage of using zinc is that it continues to prevent rusting even if the layer of zinc is damaged. Name this process of rust prevention and give any two other methods to prevent rusting.
The graph of voltage vs current for four different materials is shown below.
Which of these four materials would be used for making filament of bulb?
