Advertisements
Advertisements
Question
What is the use of earthing wire?
Advertisements
Solution
- Earthing wire is used to protect one from an electric shock.
- It does this by providing a path for a fault current to flow to the earth.
- It also causes the protective device (fuse) to switch off the electric current to the circuit that has the fault.
APPEARS IN
RELATED QUESTIONS
Draw a schematic diagram of a circuit consisting of a battery of three cells of 2 V each, a 5 Ω resistor, an 8 Ω resistor, and a 12 Ω resistor, and a plug key, all connected in series.
Redraw the circuit of question 1, putting in an ammeter to measure the current through the resistors and a voltmeter to measure the potential difference across the 12 Ω resistors. What would be the readings in the ammeter and the voltmeter?
Draw circuit symbols for
A closed switch
What is a circuit diagram
Who will spend more electrical energy? 500 W TV Set in 30 mins, or 600 W heater in 20 mins?
The accompanying figure shows some electrical appliances connected in a circuit in a house. Answer the following questions.
- By which method are the appliances connected?
- What must be the potential difference across individual appliances?
- Will the current passing through each appliance be the same? Justify your answer.
- Why are the domestic appliances connected in this way?
- If the T.V. stops working, will the other appliances also stop working? Explain your answer.
In an electric circuit, electron flow a from of point of ______ potential to the point of ______ potential.
Distinguish between a closed circuit and an open circuit, with the use of suitable labelled diagrams.
Match the column ‘A’ with column ‘B’.
|
Column ‘A’
|
Column ‘B’ |
|
(1) Eka - boron
|
(a) Germanium
|
|
(2) Eka - Aluminium
|
(b) Scandium
|
|
(3) Eka - Silicon
|
(c) Gallium |
What do you understand by the closed electric circuit
Name the instrument used to control current in an electric circuit.
The unit of electrical power is _______.
What is the potential difference?
Flow of electricity through a closed circuit is _____.
______ is the device used to close or open an electric circuit.
______ is the device used to close or open an electric circuit.
Rahul wants to make an electric circuit. He has a bulb, two wires, a safety pin, and a piece of copper. He does not have any electric cell or battery. Suddenly he gets some idea. He uses lemon instead of a battery and makes a circuit. Will the bulb glow?
In which among the following circuits does the bulb glow?
Which of the following a simple circuit must-have?
Fuse is
What is electric circuit?
What is the role of the earth wire in domestic circuits?
Explain about domestic electric circuits. (circuit diagram not required)
In a circuit, if the key is in open (off) condition, then electricity will not flow.
In the following circuits (Figure), heat produced in the resistor or combination of resistors connected to a 12 V battery will be
 |
 |
 |
| (i) | (ii) | (iii) |
In an electrical circuit three incandescent bulbs A, B and C of rating 40 W, 60 W and 100 W respectively are connected in parallel to an electric source. Which of the following is likely to happen regarding their brightness?
Name the device used these days in place of electric fuses in electrical circuits.
Draw the symbols of the following circuit components.
Switch in off position
The ______ is a species of fish that can give electric shocks of up to six hundred fifty watts of electricity.
In the following arrangement shown in the following figure, the bulb will not glow if the ends A and B are connected with
Paheli is running short of connecting wires. To complete an electric circuit, she may use a ______.
Will the bulb glow in the circuit shown in the following figure? Explain.
Paheli connected two bulbs to a cell as shown in the following figure.
She found that filament of bulb B is broken. Will the bulb A glow in this circuit? Give reason.
Overloading of electric circuits can lead to short-circuiting.
A complete circuit is left on for several minutes, causing the connecting copper wire to become hot. As the temperature of the wire increases, the electrical resistance of the wire
