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प्रश्न
State four most common electrical appliances based on heating effect of electric current. Why do we use finely heated platinum wire in surgery?
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उत्तर
The four most common appliances based on the heating effect of electrical current are electric iron, electric heater, electric oven and electric toaster. Finely heated platinum wire is used in surgery for cutting tissues much more efficiently than a knife.
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संबंधित प्रश्न
Compute the heat generated while transferring 96000 coulomb of charge in one hour through a potential difference of 50 V.
Why is the tungsten used almost exclusively for filament of electric lamps?
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?
Give two reasons why nichrome alloy is used for making the heating elements of electrical appliances.
An electric iron of resistance 20 ohms draws a current of 5 amperes. Calculate the heat produced in 30 seconds.
A heating coil has a resistance of 200 Ω. At what rate will heat be produced in it when a current of 2.5 A flows through it?
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.
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.
Identify the figure and give its use.
Name any six domestic appliances based on the heating effect of electric current.
The electricity bill specifies the usage in _______.
Find the odd one out and give its explanation.
What is the heating effect of electric current?
Write scientific reason.
A coil made up of alloy Nichrome is used in the electric heater cooker as a resistor.
Explain the importance/uses of fuse wire.
Define fuse.
Name some devices that run using heat effect of electric current
Which of the following gases are filled in electric bulbs?
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.
(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).
An electric component used as a safety device is electric circuit is ______.
When a switch is in OFF position,
- circuit starting from the positive terminal of the cell stops at the switch.
- circuit is open.
- no current flows through it.
- current flows after some time.
Choose the combination of correct answer from the following.
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.
What are the uses of electromagnets?
______ wire is used in the filament of the bulbs.
Copper wire offers very little ______ and does not get heated up quickly.
Name a few appliances which work on the basis of the heating effect of current.
In the electric equipment producing heat like iron, electric heater, boiler, toaster etc., an alloy such as nichrome is used, not pure metals.
In which of the following applications of Iron, rusting will occur most? Support your answer with valid reason.
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An electric kettle of 2 kW is used for 2h. Calculate the energy consumed in
- kilowatt hour and
- joules.
What is the heating effect of electric current?
Write an expression for the amount of heat produced in a resistor when an electric current is passed through it stating the meanings of the symbols used.
State the law that explains the heating effect of current with respect to the measurable properties in an electrical circuit.
