Advertisements
Advertisements
Question
If the current flowing through a fixed resistor is halved, the heat produced in it will become:
Options
double
one-half
one-fourth
four times
Advertisements
Solution
one-fourth
Explanation:
This is so because the heat produced is directly proportional to the square of the current passing through the resistor.
APPEARS IN
RELATED QUESTIONS
An electric iron of resistance 20 Ω takes a current of 5 A. Calculate the heat developed in 30 s.
Write Joule's law of heating.
What is nichrome? State its one use.
An electric kettle rated at 220 V, 2.2 kW, works for 3 hours. Find the energy consumed and the current drawn.
Explain why, the current that makes the heater element very hot, only slightly warms the connecting wires leading to the heater.
The heat produced in a wire of resistance 'x' when a current 'y' flows through it in time 'z' is given by:
(a) x2 × y × z
(b) x × z × y2
(c) y × z2 × x
(d) y × z × x
Identify the figure and give its use.

Give scientific reason :
In the electric equipment producing heat e.g. iron, electric heater, boiler, toaster, etc., an alloy such as Nichrome is used, not pure metals.
Name any six domestic appliances based on the heating effect of electric current.
Find the odd one out and give its explanation.
What is the heating effect of electric current?
What is overloading?
Explain the application of heating effect of electric current in an electric bulb with a diagram.
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.
Copper wire offers very little ______ and does not get heated up quickly.
Fuse is a strip of alloy wire which is made up of lead and tin with a very low ______.
Name the effect of the current responsible for the glow of the bulb in an electrical circuit.
A fuse is used in an electric circuit to stop high currents flowing through the circuit.
Explain why fuse wire is always connected in a series arrangement.
