Test: Basic Science- 2 - Class 8 MCQ

If there is a large amount of rainfall in as short period of time, it results in the flood. The flood not destroy not only homes but also the agricultural crops which later lead to starvation. There is famine in a place where flood destroy crops as there is an extreme scarcity of food.

Gravity is the force that attracts two objects. Gravity is responsible for many of the structures in the universe. On Earth, it gives weight to physical objects and causes the tides. One of the best examples of gravity is when a person drops a ball and it falls to the ground.

Echo is distinct, reflected sound wave from a surface. Principle of echo is used in echo sounder to find the depth of a sea or the location of shoals of fish. It is a reflection of sound that arrives at the listener with a delay after the direct sound. A true echo is a single reflection of the sound source.

Filtration is a process in which insoluble matter is separated from a liquid. Filtration is a separation process in which a mixture is passed through a filter that allows one component to pass-through but blocks another component from passing through because of its matter and consistency.
Heterogeneous mixtures can be separated into their respective constituents. For example, a mixture of mud and water can be separated through filtration process easily, because water being liquid will pass through the filter paper easily but the mud will not because of it being solid.

Chemical elements are those elements which cannot be chemically interconverted or broken down into simpler substances and are primary constituents of matter. They are fundamental ingredients of all matte in existence which came be combined in reaction to create a chemical substance. Each chemical element in the universe has unique properties that distinguish it from all of the other chemical elements. For example, Hydrogen is an element.

Omnivores are animals that eat both plants and animals. For example - Bears, raccoons, crows, and most humans are omnivores.
Horses are part of the herbivore family as they only eat plant material.
Fruit bats are herbivores, more specifically frugivores, as the bulk of their diet consists of fruit.
Leopards are carnivores, which means they are animals that only eat meat.
So, the correct answer is option C.

Physical change is a change in which nothing new is formed. It is a change which only affects the form of a substance, but not it's chemical composition. Such kind of change is reversible. For example melting of ice, freezing of water etc.

Sodium thiosulphate is a chemical which is readily soluble in water and is a mild reducing agent. Because of its tendency to dissolve silver salts, it is majorly used in photography for developing the film.
It is also used in chrome-tanning leather and in chemical manufacturing. It is also called sodium hyposulfite or hypo.

Fathometer is a type of sonic depth finder. It is an instrument that uses sound waves to determine the depth of water.

The astronomers usually use light-years to measure the distance between stars. A light-year is a distance of light that can travel in one year. The astronomers also use parsec. One parsec is equal to 3.3. light year's.