PHYSICS [1 Mark Question Answer]

The speed of light is very fast as compared to the speed of sound in air. So, the thunder is seen fast and then we hear the sound of a thunderstorm.

A lightning conductor is a device used to protect the large buildings against lightning during a thunderstorm.

At Home: Use of bioenergy for cooking and lightening, use CFLs instead of filament bulbs, keep the electrical appliances off after the needed period of time.

At School: Use of solar cells to light up the electricity in schools and do rainwater harvesting, keep the electrical appliances off after the needed period of time.

The neutral point is the point where the magnetic field of the magnet is equal to the magnitude of the earth's horizontal magnetic field but in the opposite direction.

Magnetic Meridian: It is the vertical plane containing the magnetic axis of a freely suspended magnet at rest under the earth's field.

The angle of Dip: The angle between the horizontal and earth's magnetic field is known as the angle of dip.

The angle of declination: The angle between geographic and magnetic meridian is called the angle of declination.

Geographic Meridian: It is the vertical plane containing the geographic north and south poles of the earth and passing through the given place on the surface of earth.

Magnetic induction is the process in which magnetism is acquired by the magnetic material when a magnet is brought near it.

The friction between two bodies when they are rubbed against each other is the reason for electrification.

Iron has high susceptibility and low retentivity means it acquires the magnetism faster and removes it soon as well. While , steel has low susceptibility and high retentivity.

Natural magnets are the pieces of lodestone which are found in nature while artificial magnet is the magnetized piece of iron or steel.

Magnetic materials get attracted towards the magnet but non-magnetic materials does not get attracted towards the magnet.

The Laws of Magnetism: Like poles repel each other and unlike poles attract each other.

The flow of electrons is the flow of negative charges inside the conductor while the flow of conventional current is the flow of positive charges inside a conductor.

When the two bulbs will be connected in parallel then the resistance of the circuit will decrease so the brightness of the bulb will increase.

When two bulbs will connect in series then resistance of the circuit will increase so the brightness of the bulbs will decrease.

Closed Circuit: The circuit in which current flows without any obstruction then it's a closed circuit.

Open Circuit: In the circuit, if the switch is off or the wire is cut then flow of current in circuit stops and we say that its an open circuit.

Potential Difference: It is defined as the amount of work done in moving a charge from one point to another

Resistance of the conductor: It is the property of the conductor by virtue of which it obstructs the flow of current in the circuit.

The B will be charged by the charging by contact. The charge on A will spread on B.

The charge gained by the B will be positive charge

By breaking the magnet into two halves, magnetic strength will always get half. So, the raio of magnetic strength will be 1:2.

By breaking the magnet into two halves, magnetic strength will always get half.

The magnetic field of lines is the lines that get formed by joining the poles of the magnet and they are the continuous curves in which tangent drawn to it will give the direction of the magnetic field.

An atom does not have any net charge while ion is either a positive charge or a negative charge.

The magnets (pieces of lodestone) found in nature are called a natural magnet.

A galvanometer is used to detect the direction of the current as well as to detect very weak currents. An ammeter is used to measure the magnitude of an electric current in the circuit.

The resistance of the wire will become 4 ohms.

With the increase in temperature of the wire, the resistance of wire increases.

The effect on the rate of flow of current by the wire is called its electrical resistance. Its S.I unit is the ohm.

A key is used to put the current on and off in the circuit.

Q = I.t = 4.5 x 2.5 = 11.25 C.

A cell is a source of energy which converts the chemical energy into electrical energy. The cell consists of two electrodes in the form of a conducting rod immersed in the solution called an electrolyte.

The points of the magnet where attraction appears the maximum are called poles of a magnet and they are situated at ends of the magnet.

The magnetism acquired by a magnetic material when it is kept near a magnet is called induced magnetism.

Horse-shoe magnet is the shape of the magnet. This shape helps in bringing the poles near to each other and make a strong magnet.

The net charge on an atom is zero.

A rheostat is used to control current in an electric circuit.

I = Q/t = 0.8/5 = 0.16 Ampere.

The resistance of the conductor is 1 ohm when a current of 1 ampere flows through it when the potential difference across it is 1 volt.

S.I unit of resistance is the ohm.

An ammeter is always connected in series in the circuit.

A voltmeter is always connected in parallel to the circuit.

An artificial magnet is the magnetized piece of iron or steel.

The voltmeter has high resistance than the ammeter.

Electrons flow inside the metallic conductor and a battery and cell help in the movement of electrons in it.