Science [1 Marks Each] QUE - ANS

The reflector helps in reflecting the light into a focussed area.

This is because electric energy changes into heat energy.

Take an electric circuit, keep the terminals unconnected in the air. The bulb do not glow, as air is an insulator and does not allow the current to flow through it.

Electric cell: Alessandro Volta.
Electric bulb: Thomas Alva Edison.

Conductors: Copper wire, pencil lead.
Insulator. Eraser, paper, matchstick, polythene.

A conductor is that which easily allows the passage of current through it. Example: Aluminium or any metal.
An insulator is that which does not allow the passage of current through it. Example: Rubber.

Filament.

Insulators are used in making switchboard, handles of testers, screw drivers.

An electric circuit in which electrical contact at any point is broken is called open circuit.

 A device which converts solar energy into electrical energy.

It is a device which converts chemical energy into electrical energy.

Zinc metal plate.

Carbon rod with a metal cap on it.

Yes, if the object is good conductor of electricity then current will pass through conduction tester and the bulb will glow. Hence the object will be a conductor of electricity.

Yes, the electric circuit is closed so the bulb will glow.

No, since eraser is an insulator so it does not allow the current to pass. Hence the bulb will not glow.

Electric switch is used to make electric circuit open or closed for a particular appliance and hence with the help of a switch we can use an appliance according

The bulb would not glow in the arrangement shown in figure because the one end of tester/screw driver is made up of plastic which does not allow the electric current to flow through it.

Do it yourself.

The Big Dipper appears to move around the Pole Star due to the rotation of the Earth. Over a few hours, its position changes, making it seem as if it is rotating around the Pole Star.

During the day, the Sun’s bright light outshines the stars, making them invisible to our eyes. The atmosphere scatters the sunlight, creating the blue sky and masking the faint light of the stars.

The order of the planets in the figure is not correct. The correct order from the Sun is: Mercuiy, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

Sirius

The diagram that shows the path of electric current is called electric circuit.

The scientific study of universe is called Astronomy.

The Universe is a large space consisting of celestial bodies like the stars, planets, galaxy, dust and gases.

Our galaxy is called the Milky Way because it appears as a milky hand of light in the sky when we see it in a really dark area.

Milky Way galaxy is often known as Akash Ganga.

Our Milky Way Galaxy is a spiral galaxy having a whitish broadand. It looks like a spinning pinwheel when viewed from top or bottom.

A galaxy is a huge system of billions of stars, and clouds of dust and gases.

Venus is considered as ‘Earth’s-twin’ because its size and shape are very much similar to that of the earth.

Outer planets are also called Jovian planets. They are- Jupiter, Saturn, Uranus and Neptune.

Inner planets are also called Terrestrial planets, They are – Mercury, Venus, Earth and Mars.

Artificial satellites are used for weather forecasting, long distance communication and remote sensing.

Jupiter revolves around itself with a great speed; hence Jupiter is called the Stormy planet.

‘National Space Day’ is celebrated on August 23rd every year.

A small sized celestial body that revolves independently around the sun is called the dwarf planet.

Venus is usually seen shining brightly at dawn and dusk, and is commonly called the Morning Star or the Evening Star, even though it is not a star,

Mars is called the Red Planet because it appears red. This is because the soil on Mars is reddish in colour.

The Moon isn’t a planet because it orbits the Earth.

The planets orbit around the Sun.

Four planets are made out of gas and they are also referred to as gas giants. They are Jupiter, Saturn, Uranus, and Neptune.

Venus is the hottest planet in our solar system.

Our solar system is in the Milky Way Galaxy.

The motion of the earth around the sun in its orbit is known as revolution.