Advertisements
Advertisements
Question
What is the use of earthing wire?
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
What do the following symbols mean in circuit diagrams?
Tell the odd one out. Give proper explanation.
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
Resistances R1, R2, R3 and R4 are connected as shown in the figure. S1 and S2 are two keys. Discuss the current flowing in the circuit in the following cases.
- Both S1 and S2 are closed.
- Both S1 and S2 are open.
- S1 is closed but S2 is open.
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.
Draw a neat diagram showing a open electric circuit.
Name the instrument used to control current in an electric circuit.
Explain the following:
Open circuit
What is the potential difference?
Increasing the current passing through the wire decreases the magnetic field intensity.
Nowadays MCBs are used in homes, for stop the current in the circuit which suddenly increases.
Flow of electricity through a closed circuit is _____.
______ is the device used to close or open an electric circuit.
In the given circuit diagram, which of the given switch(s) should be closed. So that only bulb A glows.
Tabulate the different components of an electric circuit and their respective symbols.
In which of the following circuits are the bulb connected in series?
Study the electric circuit below. Which of the following switches should be closed so that only two bulbs will light up
Three bulbs are connected end to end from the battery. This connection is called _______.
When a circuit is open, _____ cannot pass through it.
The wiring in a house consists of ______ circuits.
What is the role of the earth wire in domestic circuits?
______ is a kind of fish which is able to produce an electric current.
In a circuit, if the key is in open (off) condition, then electricity will not flow.
What are the types of electric circuits?
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?
Draw a circuit diagram of an electric circuit containing a cell, a key, an ammeter, a resistor of 2Ω in series with a combination of two resistors (4Ω each) in parallel and a voltmeter across the parallel combination. Will the potential difference across the 2Ω resistor be the same as that across the parallel combination of 4Ω resistors? Give reason.
When an electric current flows through a copper wire AB as shown in Figure14.1, the wire
In the above circuit, if the current reading in the ammeter A is 2A, what would be the value of R1?
Paheli connected two bulbs to a cell as shown in Fig. 12.8.
She found that filament of bulb B is broken. Will the bulb A glow in this circuit? Give reason.
Boojho has a cell and a single piece of connecting wire. Without cutting the wire in two, will he be able to make the bulb glow? Explain with the help of a circuit diagram.
Write a short note on the different electrical circuits.
Assertion: People struck by lightning receive a severe electrical shock.
Reason: Lightning carries very high voltage.
Set up the circuit shown in Figure again. Move the key to ‘ON’ position and watch carefully in which direction the compass needle gets deflected. Switch ‘OFF’ the current. Now keeping rest of the circuit intact, reverse the connections at the terminal of the cell. Again switch ‘on’ the current. Note the direction in which the needle gets deflected. Think of an explanation.
