Advertisements
Advertisements
प्रश्न
If the current flowing through a fixed resistor is halved, the heat produced in it will become:
पर्याय
double
one-half
one-fourth
four times
Advertisements
उत्तर
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
संबंधित प्रश्न
Why does the cord of an electric heater not glow while the heating element does?
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 are the coils of electric irons and electric toasters made of an alloy rather than a pure metal?
Name the material which is used for making the filaments of an electric bulb.
Which electric heating device in your home do you think have resistors which control the flow of electricity?
Identify the figure and give its use.

Find the odd one out and give its explanation.
What is a short circuit?
Live wire and neutral wires have a 220 V potential difference.
What does overloading cause?
Define fuse.
How does use of a fuse wire protect electrical appliances?
(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 are the factors affecting heating effect of electric current?
______ wire is used in the filament of the bulbs.
Name the effect of the current responsible for the glow of the bulb in an electrical circuit.
An electric fuse is a wire made up of a material having ______ melting point.
Tara, after completing her exams, went to her grandmother's house along with her younger brother Rahul. One day, Rahul came home after playing and switched on the fan and air conditioner. At the same time, his grandmother was preparing a milkshake for him using a mixer. Suddenly, they heard a big sound and the electricity of the house got shut down. Tara is called an electrician. He said the main reason for supply to shut down was overloading.
- What is overloading?
- Is overloading and short the same? When does short-circuiting take place?
- How can the effects of overloading be avoided?
