Advertisements
Advertisements
Question
Explain the importance/uses of fuse wire.
Advertisements
Solution
- Fuse is an important application of heating effect of electric current used in electric circuits.
- It protects circuits and appliances by stopping the flow of any excess electric current.
- If a current larger than the specific value flows through the circuit, the temperature of fuse wire increases. This melts the fuse wire and breaks the circuit.
- In summer season, when consumption of electrical power is huge in the evening due to home lighting, fan, air conditioner, use of electricity in shops etc, an excessive current is drawn from the transformer. If the capacity of the transformer is insufficient, its fuse wire melts, and the supply gets shut down.
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?
Compute the heat generated while transferring 96000 coulomb of charge in one hour through a potential difference of 50 V.
Write Joule's law of heating.
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?
An electric room heater draws a current of 2.4 A from the 120 V supply line. What current will this room heater draw when connected to 240 V supply line?
How does the resistance of a wire vary with its:
diameter?
How much heat will an instrument of 12 W produce in one minute if it is connected to the heat produced by it?
Name the material which is used for making the filaments of an electric bulb.
Which of the following characteristic is not suitable for a fuse wire?
(a) thin and short
(b) thick and short
(c) low melting point
(d) higher resistance than rest of wiring
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.
Which electric heating device in your home do you think have resistors which control the flow of electricity?
Three heaters each rated 250 W, 100 V are connected in parallel to a 100 V supply. Calculate:
- the total current taken from the supply
- the resistance of each heater and
- the energy supplied in kWh to the three heaters in 5 hours.
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.
Give a scientific reason:
For electric power transmission, copper or aluminium wire is used.
Why does tungsten metal used to make solenoid type coil in an electric bulb?
Name the factors on which the heat produced in a wire depends when current is passed in it, and state how does it depend on the factors stated by you.
Name any six domestic appliances based on the heating effect of electric current.
What is used to turn off the sudden increase in current in the electrical circuit of the house nowadays?
Write two devices based on the heating effect of electric current.
Explain the application of heating effect of electric current in an electric bulb with a diagram.
Explain the heating effect of electric current.
Which of the following is correct?
The heating element of an electric iron is made up of:
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?
How does use of a fuse wire protect electrical appliances?
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?
An electric component used as a safety device is electric circuit is ______.
Can we use the same fuse in a geyser and a television set? Explain.
Name two electric devices for each where
- heating effect of current is used and
- magnetic effect of current is used.
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.
______ wire is used in the filament of the bulbs.
Fuse is a strip of alloy wire which is made up of lead and tin with a very low ______.
Match the following
| 1. | Bulb | a. | Conductor |
| 2. | Electroplating | b. |
Insulator |
| 3. | Pure water | c. | Heating effect of current |
| 4. | Salt solution | d. | Chemical effect of current |
An electric fuse is a wire made up of a material having ______ melting point.
Explain why fuse wire is always connected in a series arrangement.
In which of the following applications of Iron, rusting will occur most? Support your answer with valid reason.
| A | B | C | D |
 |
 |
 |
 |
