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प्रश्न
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?
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संबंधित प्रश्न
Why is a series arrangement not used for connecting domestic electrical appliances in a circuit?
Why does the connecting cord of an electric heater not glow hot while the heating element does?
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
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.
Which electric heating device in your home do you think have resistors which control the flow of electricity?
Give Scientific reason.
In practice, the unit kWh is used for the measurement of electrical energy, rather than joule.
The ‘live’ and the ‘neutral’ wires have potential difference of _______.
Which of the following substance contracts on heating?
Find the odd one out and give its explanation.
What is a short circuit?
Write two devices based on the heating effect of electric current.
Mark the correct choice
- Assertion: Electric appliances with a metallic body have three wire connections.
- Reason: Three-pin connections reduce the heating of the connecting wires.
Why is parallel arrangement used in domestic wiring?
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.
An MCB can be used instead of a fuse in an electrical circuit.
What are the factors affecting heating effect of electric current?
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 |
A fuse is used in an electric circuit to stop high currents flowing through the circuit.
Define the following:
Electrolyte
Anannya responded to the question: Why do electrical appliances with metallic bodies are connected to the mains through a three-pin plug, whereas an electric bulb can be connected with a two-pin plug?
She wrote: Three-pin connections reduce heating of connecting wires.
- Is her answer correct or incorrect? Justify.
- What is the function of a fuse in a domestic circuit?
