4) Electricity and Magnetism

Question 1

Define Magnetic poles

Answer 1

Magnetic poles are the regions on the ends of a magnet , where there are the magnetic field lines that either emerge from it, or are directed towards it.

Question 2

Define Magnets

Answer 2

Magnets are materials that can produce their own magnetic fields and hence are able to attract magnetic substances towards them.

Question 3

Define Magnetic materials:

Answer 3

Magnetic materials are substances that get attracted towards a magnet

Question 4

Define Domains:

Answer 4

Magnetic domains are regions within a magnetic material in which the magnetisation is present in a uniform direction

Question 5

Domain:

Answer 5

A domain is a region inside of a material where groups of magnetic moments naturally align in the same direction.

Question 6

Define induced magnetism:

Answer 6

When a magnetic substance is brought close to a magnet, it stays attracted to the magnet as long as it is not pulled away from the magnet’s magnetic field. So, we say that the magnetism is induced in the magnetic material as long as it is in the magnets magnetic field.

Question 7

Define Temporary magnets:

Answer 7

Temporary magnets are made up of soft ion and stay magnetised for some time.

Question 8

Define Permanent magnets:

Answer 8

Permanent magnets retain their magnetic properties even in the absence of an inducing field or current

Question 9

Define Electromagnets:

Answer 9

Electromagnets are magnets in which their magnetic field is produced due to an electric current. They usually have iron cores and lose their magnetism when the electric current through them is stopped.

Question 10

Define Magnetic field:

Answer 10

:It is the region around a magnetic material within which the force of magnetism acts on magnetic materials.

Question 11

Define Bar magnets:

Answer 11

Bar magnets that are rectangular in shape and have permanent magnetic properties and are made from the ferromagnetic substances

Question 12

Define Magnetic field lines:

Answer 12

magnetic field lines are imaginary lines around the magnet and their direction is always from the North to South pole of the magnet These are more concentrated towards the poles and never overlap each other

Question 13

Define Compass:

Answer 13

A compass has a magnetic needle that always points in the North-South direction. The red painted part of it indicates North. Hence is used to find direction while navigating or even to find the direction of magnetic field lines , if placed near a permanent magnet.

Question 14

Define Iron filings:

Answer 14

These are small shavings of a ferromagnetic material

Question 15

Define Electric charge:

Answer 15

An electric charge is a basic physical property that causes objects to feel attracted or repelled towards each other

Question 16

Define Positive charge:

Answer 16

A positive charge exists when the number of protons exceeds the number of electrons .

Question 17

Electric Field:

Answer 17

An electric field as a region in which an electric charge experiences a force

Question 18

Define Negative charge:

Answer 18

A negative charge exists when the number of protons is less than the number of electrons .

Question 19

Define Electrostatic charge:

Answer 19

Electrostatic charge is a charge that is developed on ungrounded or insulating surfaces, as a result of either a deficiency or an excess of electrons .

Question 20

Define A point charge:

Answer 20

A point charge is a hypothetical charge located at a single point in space .It only exists in theory and cannot be measured.

Question 21

Define A conducting sphere:

Answer 21

A conducting sphere is a sphere that has the charge present only on its surface

Question 22

Define Electrical conductors:

Answer 22

Electrical conductors are substances or material that allow electricity to flow through them .

Question 23

Define Electrical insulators:

Answer 23

Electrical insulators are substances or material that do not allow electricity to flow through them .

Question 24

Define Electric current:

Answer 24

An Electrical current is defined as the rate at which the charge flows.

Question 25

Define Conventional current:

Answer 25

Conventional current assumes that current flows out of the positive terminal, through the circuit and into the negative terminal of the source.

Question 26

Define Ammeter:

Answer 26

:It is an instrument to measure the electric current

Question 27

Define Alternating current:

Answer 27

An alternating current is an electric current that periodically reverses it’s direction and changes it’s magnitude continuously with time

Question 28

Define Direct current:

Answer 28

Direct current is the one-directional flow of electric charge

Question 29

Define Electromotive force:

Answer 29

It is the electrical work done by a source in moving a unit charge around a complete circuit

Question 30

Define Potential difference:

Answer 30

It is the work done by a unit charge passing through a component

Question 31

Define Electrical power:

Answer 31

It is the rate at which electrical energy is transferred by an electric circuit.

Question 32

Define Kilowatt-hour (kWh):

Answer 32

It is a unit of energy and this term tells us that one kilowatt (1 kW) of power is spent in one hour (1 h) of time