Advertisements
Advertisements
प्रश्न
Read the given passage and answer the following questions:
The home electrical connection consists of ‘live’, ‘neutral’ and ‘earth’ wires. The ‘live’ and the ‘neutral’ wires have potential difference of 220 V. The ‘earth’ is connected to ground. Due to a fault in the equipment or if the plastic coating on the ‘live’ and the ‘neutral’ wires gives a way the two wires come in contact with each other and a large current flows through it producing heat. If any inflammable material (such as wood, cloth, plastic, etc.) exists around that place it can catch fire. Therefore a fuse wire is used as a precautionary measure.
- Name the two wires having potential difference of 220 V.
- What is a short circuit?
- Write the function of a fuse.
Advertisements
उत्तर
- The ‘live’ and the ‘neutral’ wires have potential difference of 220 V.
- Due to a fault in the equipment or if the plastic coating on the ‘live’ and the ‘neutral’ wires gives away the two wires come in contact with each other and a large current flows through it producing heat. This is known as short circuiting.
- Fuse wire protects circuits and appliances by stopping the flow of any excess electric current.
APPEARS IN
संबंधित प्रश्न
An electromagnet does not attract a piece of iron.
Fill in the following blank with suitable words:
If a coil is viewed from one end, and the current flows in a clockwise direction, then this end is a ........... pole.
What is Maxwell's corkscrew rule? For what purpose is if used?
If the direction of electric current in a solenoid when viewed from a particular end is anticlockwise, then this end of solenoid will be:
(a) west pole
(b) south pole
(c) north pole
(d) east pole
For the coil in the diagram below, when the switch is pressed:
(a) what is the polarity of end A?
(b) which way will the compass point then?
The north pole of a long bar magnet was pushed slowly into a short solenoid connected to a galvanometer. The magnet was held stationary for a few seconds with the north pole in the middle of the solenoid and then withdrawn rapidly. The maximum deflection of the galvanometer was observed when the magnet was ______.
A coil is connected to a galvanometer. When the N-pole of magnet is pushed into the coil, the galvanometer deflected to the right. What deflection, if any, is observed when:
the S-pole is inserted?
In the Activity shown below, how do we think the displacement of rod AB will be affected if
- current in rod AB is increased
- a stronger horse-shoe magnet is used
- length of the rod AB is increased?
|
(c) Considering the relationship in the first pair, complete the second paie :
AgCI : White :: CuI2 : ___________
Name any two appliances which works on the phenomenon of magnetic effect of electric current.
Identify the given figure, write the labels of it.
A soft iron bar is introduced inside the current-carrying solenoid. The magnetic field inside the solenoid ____________.
What is that instrument which can detect the presence of electric current in a circuit?
A uniform magnetic field exists in the plane of paper pointing from left to right as shown in Figure. In the field an electron and a proton move as shown. The electron and the proton experience
In the arrangement shown in Figure there are two coils wound on a non-conducting cylindrical rod. Initially the key is not inserted. Then the key is inserted and later removed. Then
Unscramble the following words:
HTRCO
Boojho made an electromagnet by winding 50 turns of wire over an iron screw. Paheli also made an electromagnet by winding 100 turns over a similar iron screw. Which electromagnet will attract more pins? Give reason.
What do you mean by the magnetic effect?
Make four electromagnets with 20, 40, 60 and 80 turns. Connect them one by one to a battery of 2 cells. Bring the electromagnet near a box of pins. Count the number of pins attracted by it. Compare the strengths of the electromagnets.
