Science [1 Marks Each] QUE - ANS

When a beam of light falls on a rough surface it is turned back in different directions. It is called scattering of light.

 A dark outline or patch formed by an opaque object that blocks light coming from a source of light is called shadow. The colour of an opaque object does not affect the colour of the shadow.

When light rays after striking the smooth and shiny surface return to same medium, this phenomenon is called reflection of light.

Shadow is formed when light does not reach behind the opaque object kept in the path of light

The bodies which emit light when heated to a very high temperature are called incandescent bodies. Example: electric bulb.

Moon is non-luminous body because it shines by reflecting the sunlight falling on it.

The less darker shadow formed penumbra.on the periphery of dark shadow is called penumbra.

Shadow is the dark space behind an opaque object where light does not reach.

Sun is a natural source of light.

Light ray travels in a straight line.

Umbra is the dark region behind object facing light which does not receive light at all.

Moon is non-luminous body.

No, in a completely dark room no image will be formed because there is no light in the room so no reflection of light takes place and no image will be formed.

Renewable and non-renewable natural resources are the two types of natural resources.

Resource is a source of supply that is kept in reserve in order to be converted into something more valuable – and helpful.

Energy sources can be divided into renewable energy sources and non¬renewable energy sources.

Solar energy, wind energy, hydropower, tidal energy, and geothermal energy are some of the important sources of renewable energy.

Natural resources that are limited in quantity are referred to as non¬renewable resources. These resources cannot be supplied or regenerated in a short duration of time. These resources cannot be reused.

Compressed Natural Gas.

Diesel is used as a fuel for heavy motor vehicles and electric generators.

Kerosene is used as fuel in jet aircraft engines.

Diesel is used as a fuel for electric generators.

Liquefied petroleum gas.

Any natural mass of mineral matter that makes up the earth’s crust is called a rock.

Wooden plough, iron plough, and soil plank.

The ploughed field may have big pieces of soil called crumbs.

Soil is made up of small pieces of broken rock and decaying plants.

The dense bushes and the tall grasses provide the food and shelter to the animals. They also protect them from carnivores that live in the forest.

The forest floor looks dark- coloured and is covered with a layer of dead and decaying leaves, fruits, seeds, twigs and small herbs. The decaying matter is moist and warm. Walking over the dead leaf layer on the forest floor is like walking over a spongy carpet.

Van-Mahotsav is a week-long event celebrated across the country during the month of July. It is a forest festival during which new plants and trees are planted and awareness about respecting forests is raised.

Sun is the ultimate source of energy for all living organisms.

Sun

Sea and ocean water contains large amounts of various salts. It is due to these salts the ocean water is salty and cannot be used for drinking, washing and for irrigation purposes.

Water exists on the earth in all three physical forms : Ice, water and water vapour.

Oceans, Rivers, Springs, Tubewells, Rain water, etc.

The availability of air decreases gradually as we go up in the atmosphere.

Our earth is surrounded by a thin layer of air. This layer is called atmosphere. It extends up to many kilometres above the surface of the earth.

Air will become more combustible and many substances may undergo fast oxidation.

Wind is the movement of air caused by the uneven heating of the earth by the sun.