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प्रश्न
These days when current in the circuit suddenly increases _______ switches are used.
विकल्प
MCA
MCC
MCD
MCB
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उत्तर
These days when current in the circuit suddenly increases MCB switches are used.
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संबंधित प्रश्न
State four most common electrical appliances based on heating effect of electric current. Why do we use finely heated platinum wire in surgery?
An electric heater of resistance 8 Ω draws 15 A from the service mains 2 hours. Calculate the rate at which heat is developed in the heater.
How does the resistance of a wire vary with its area of cross-section?
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?
Give two reasons why nichrome alloy is used for making the heating elements of electrical appliances.
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?
A resistance of 25 Ω is connected to a 12 V battery. Calculate the heat energy in joules generated per minute.
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
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?
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.
Statement 1 : Electric current ( flow of electrons ) creates heat in the resistor.
Statement 2 : Heat in the resistor is created according to the rule of energy conservation.
Explain Statement 1 with the help of Statement 2.
Why does tungsten metal used to make solenoid type coil in an electric bulb?
Answer the following question:
what is the heating effect of the electric current? state any four applications of it?
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The ‘live’ and the ‘neutral’ wires have potential difference of _______.
Find the odd one out and give its explanation.
What is a short circuit?
True or False – If False give the correct answer
The fuse wire does not melts whenever there is overload in the wiring.
Heating effect of current is called ______
A fuse wire repeatedly gets burnt when used with a good heater. It is advised to use a fuse wire of:
Assertion: Bending of wire decreases the resistance of the electric wire.
Reason: The resistance of a conductor depends on length, thickness, nature of material and temperature of the conductor.
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(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 ______.
Can we use the same fuse in a geyser and a television set? Explain.
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.
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- 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.
What are the factors affecting heating effect of electric current?
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Name the effect of the current responsible for the glow of the bulb in an electrical circuit.
A student boils water in an electric kettle for 20 minutes. Using the same mains supply he wants to reduce the boiling time of water. To do so should he increase or decrease the length of the heating element? Justify your answer.
The electric fuse works on the Joule heating principle.
Explain why fuse wire is always connected in a series arrangement.
1 kWh is equal to ______.
In the electric equipment producing heat like iron, electric heater, boiler, toaster etc., an alloy such as nichrome is used, not pure metals.
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.
