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
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?
What do the following symbols mean in circuit diagrams?

Draw circuit symbols for
fixed resistance
Draw circuit symbols for
a battery of three cells
Draw circuit symbols for
an open switch
Explain with the help of a labelled circuit diagram how you will find the resistance of a combination of three resistors, or resistance R1, R2 and R3, joined in parallel. Also mention how you will connect the ammeter and the voltmeter in the circuit when measuring the current in the circuit and the potential difference across one of the three resistors of the combination.
How does the short circuit form? What is its effect?
Find the odd one out and justify it.
Fuse wire, M.C.B., Rubber Gloves, Generator
In an electric circuit, electron flow a from of point of ______ potential to the point of ______ potential.
In an electric circuit, a battery and a bulb have been connected and the battery consists of two cells of equal potential difference. If the bulb is not glowing, then which tests will you perform in order to find out the reason for the bulb not glowing?
Write the condition required for a circuit to be a closed circuit.
Answer the following question.
With the help of a suitable circuit diagram prove that the reciprocal of the equivalent resistance of a group of resistances joined in parallel is equal to the sum of the reciprocals of the individual resistances.
What do you understand by the open electric circuit?
Draw a neat diagram showing a closed electric circuit.
What is the potential difference?
______ is the device used to close or open an electric circuit.
______ is the device used to close or open an electric circuit.
Tabulate the different components of an electric circuit and their respective symbols.
In which among the following circuits does the bulb glow?
In the circuit diagram below, 10 units of electric charge move past point x every second What is the current in the circuit ______.

In which of the following circuits are the bulb connected in series?
Draw the circuit diagram for the following series connection

Study the electric circuit below. Which of the following switches should be closed so that only two bulbs will light up

Assertion: People struck by lightning receive a severe electrical shock.
Reason: Lightning carries very high voltage.
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) |
A child has drawn the electric circuit to study Ohm’s law as shown in Figure. His teacher told that the circuit diagram needs correction. Study the circuit diagram and redraw it after making all corrections.

Choose the statement which is not correct in the case of an electric fuse.
Our body is a ______ of electricity.
Observe the circuit given:
1. Would any of the bulbs glow when the switch is in the ‘OFF’ position?

2. What will be the order in which the bulbs A, B, and C will glow when the switch is moved to the ‘ON’ position?

In the above circuit, if the current reading in the ammeter A is 2A, what would be the value of R1?
Match the following
| 1. | Insulator | a. | Coulomb |
| 2. | Conductor | b. | Electric circuit |
| 3. | Closed path | c. | Copper |
| 4. | Electric charge | d. | Rubber |
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.
An electric motor rated 1100 W is connected to 220 V mains. Find:
- The current drawn from the mains,
- Electric energy consumed if the motor is used for 5 hours daily for 6 days.
- Total cost of energy consumed if the rate of one unit is 5.



