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प्रश्न
Live wire and neutral wires have a 220 V potential difference.
विकल्प
Right
Wrong
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उत्तर
Live wire and neutral wires have a 220 V potential difference- Right
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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?
Why does the cord of an electric heater not glow while the heating element does?
An electric iron of resistance 20 Ω takes a current of 5 A. Calculate the heat developed in 30 s.
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
If the current flowing through a fixed resistor is halved, the heat produced in it will become:
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?
Give a scientific reason.
Tungsten metal is used to make a solenoid type coil in an electric bulb.
Give a scientific reason:
For electric power transmission, copper or aluminium wire is used.
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.
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.
Answer the following question:
what is the heating effect of the electric current? state any four applications of it?
In an electric bulb, coil of _______ metal is used.
A coil of an alloy _______ is used in electric heater cooker as a resistor.
What is a short circuit?
What is used to turn off the sudden increase in current in the electrical circuit of the house nowadays?
True or False – If False give the correct answer
The fuse wire does not melts whenever there is overload in the wiring.
Name some devices that run using heat effect of electric current
A current of 1 A is drawn by a filament of an electric bulb. Number of electrons passing through a cross-section of the filament in 16 seconds would be roughly:
An electric bulb is connected to a 220 V generator. The current is 0.50 A. What is the power of the bulb?
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.
Why is parallel arrangement used in domestic wiring?
Your teacher has shown you the following activity.
Activity: Teacher has wound a long insulated piece of wire around an iron nail in the form of a coil. Free ends of the wire are connected to a cell through a switch as shown in the following figure. The current is switched on and some pins are placed near the ends of the nail.
Write down any three questions that come to your mind about this activity.
What are the uses of electromagnets?
Name the effect of the current responsible for the glow of the bulb in an electrical circuit.
Name a few appliances which work on the basis of the heating effect of current.
What is a trip switch?
The following is not a safety device.
An electric fuse is a wire made up of a material having ______ melting point.
A trip switch is a ______ safety device.
Explain why fuse wire is always connected in a series arrangement.
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.
| A | B | C | D |
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In a set up the students coated iron nails with zinc metal and noted that, iron nails coated with zinc prevents rusting. They also observed that zinc initially acts as a physical barrier, but an extra advantage of using zinc is that it continues to prevent rusting even if the layer of zinc is damaged. Name this process of rust prevention and give any two other methods to prevent rusting.
An electric iron of resistance 20 Ω draws a current of 5 A. The heat developed in the iron in 30 seconds is ______.
