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प्रश्न
Name any six domestic appliances based on the heating effect of electric current.
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उत्तर
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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?
How does the resistance of a wire vary with its:
diameter?
Write down the formula for the heat produced when a current I is passed through a resistor R for time t.
Explain why, the current that makes the heater element very hot, only slightly warms the connecting wires leading to the heater.
A resistance of 25 Ω is connected to a 12 V battery. Calculate the heat energy in joules generated per minute.
Derive the expression for the heat produced due to a current 'I' flowing for a time interval 't' through a resistor 'R' having a potential difference 'V' across its ends. With which name is this relation known?
The electrical resistivities of four materials P, Q, R and S are given below:
| P | `6.84xx10^8`Ωm |
| Q | `1.70xx10^8`Ωm |
| R | ` 1.0xx10^15`Ωm |
| s | `11.0xx10^-7`Ωm |
Which material will you use for making: (a) heating element of electric iron (b) connecting wires of electric iron (c) covering of connecting wires? Give reason for your choice in each case.
Give a scientific reason:
For electric power transmission, copper or aluminium wire is used.
Give Scientific reason.
In practice, the unit kWh is used for the measurement of electrical energy, rather than joule.
Identify the figure and give its use.
Heat energy is being produced in a resistance in a circuit at the rate of 100 W. The current of 3 A is flowing in the circuit. What must be the value of the resistance?
Solve the following example.
Two tungsten bulbs of wattage 100 W and 60 W power work on 220 V potential difference. If they are connected in parallel, how much current will flow in the main conductor?
Answer the following question:
what is the heating effect of the electric current? state any four applications of it?
Write the mathematical expression for Joule’s law of heating.
Compute the heat generated while transferring 96000 coulombs of charge in two hours through a potential difference of 40 V.
These days when current in the circuit suddenly increases _______ switches are used.
What is a short circuit?
Right or wrong sentence.
Live wire and neutral wires have a 220 V potential difference.
Write scientific reason.
A coil made up of alloy Nichrome is used in the electric heater cooker as a resistor.
Name any two appliances which works on the phenomenon of heating effect of electric current.
What does overloading cause?
Define fuse.
Heating effect of current is called ______
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:
Which of the following gases are filled in electric bulbs?
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?
What is Joule’s heating effect? How can it be demonstrated experimentally? List its four applications in daily life.
What are the uses of electromagnets?
Copper wire offers very little ______ and does not get heated up quickly.
An electric fuse is a wire made up of a material having ______ melting point.
A trip switch is a ______ safety device.
The electric fuse works on the Joule heating principle.
Find the odd one out.
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 kettle of 2 kW is used for 2h. Calculate the energy consumed in
- kilowatt hour and
- joules.
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.
When a current I flows through a wire of resistance R for time t then the electrical energy produced is given by ______.
