Advertisements
Advertisements
प्रश्न
An electric fuse works on the:
(a) chemical effect of current
(b) magnetic effect of current
(c) lighting effect of current
(d) heating effect of current
Advertisements
उत्तर
(d) heating effect of current
An electric fuse works on the heating effect of current.
APPEARS IN
संबंधित प्रश्न
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?
A resistance of 25 Ω is connected to a 12 V battery. Calculate the heat energy in joules generated per minute.
How much heat will an instrument of 12 W produce in one minute if it is connected to the heat produced by it?
The heat produced by passing an electric current through a fixed resistor is proportional to the square of:
(a) magnitude of resistance of the resistor
(b) temperature of the resistor
(c) magnitude of current
(d) time for which current is passed
Give a scientific reason:
For electric power transmission, copper or aluminium wire is used.
What is a short circuit?
What is used to turn off the sudden increase in current in the electrical circuit of the house nowadays?
Write scientific reason.
A coil made up of alloy Nichrome is used in the electric heater cooker as a resistor.
The heating element of an electric iron is made up of:
An electric bulb is connected to a 220 V generator. The current is 0.50 A. What is the power of the bulb?
An electric kettle consumes 1 kW of electric power when operated at 220 V. A fuse wire of what rating must be used for it?
B1, B2 and B3 are three identical bulbs connected as shown in Figure. When all the three bulbs glow, a current of 3A is recorded by the ammeter A.
- What happens to the glow of the other two bulbs when the bulb B1 gets fused?
- What happens to the reading of A1, A2, A3 and A when the bulb B2 gets fused?
- How much power is dissipated in the circuit when all the three bulbs glow together?
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.
What is Joule’s heating effect? How can it be demonstrated experimentally? List its four applications in daily life.
An electric component used as a safety device is electric circuit is ______.
Paheli took a wire of length 10 cm. Boojho took a wire of 5 cm of the same material and thickness. Both of them connected the wires as shown in the circuit given in the following figure. The current flowing in both the circuits is the same.
- Will the heat produced in both cases be equal? Explain.
- Will the heat produced be the same if the wires taken by them are of equal lengths but of different thickness? Explain.
An MCB can be used instead of a fuse in an electrical circuit.
______ wire is used in the filament of the bulbs.
Name a few appliances which work on the basis of the heating effect of current.
An electric kettle of 2 kW is used for 2h. Calculate the energy consumed in
- kilowatt hour and
- joules.
