English Medium Class 10 - CBSE Question Bank Solutions for Science

Assertion: Concave mirrors are used as reflectors in torches, vehicle head lights and in search lights.

Reason: When an object is placed beyond the center of curvature of a concave mirror, the image formed is real and inverted.

Which of the following statement is correct?

Myopia may arise due to ____________.

A student traces the path of a ray of light passing through a rectangular slab.

For measuring the angle of incidence, he must position the protractor in the manner shown in the figure:

An object is placed at a distance of 0.25 m
in front of a plane mirror. The distance between the object and image will be ______.

Which of the following correctly represents a balanced chemical equation?

Why is it important to balance a skeletal chemical equation?

Which form of carbon is found in Golkonda mines of Karnataka?

Which of the following statements about graphite and diamond is true?

What is the difference between genetic drift and change due to natural selection?

The transfer of energy in a food chain is always ______.

If the real image of a candle flame formed by a lens is three times the size of the flame and the distance between lens and image is 80 cm, at what distance should the candle be placed from the lens?

Observe the food web and answer the questions given below:

The mussel can be described as:

Observe the food web and answer the questions given below:

In the food web, what two organisms are competing for food?

Name the type of mirror used in the following situation:

Side/rear-view mirror of a vehicle

Support your answer with reason.

Name the type of mirror used in the following situation:

Solar furnace

Support your answer with reason.

Solid calcium oxide reacts vigorously with water to form calcium hydroxide accompanied by liberation of heat. This process is called slaking of lime. Calcium hydroxide dissolves in water to form a solution called lime water. Which among the following is (are) true about slaking of lime and the solution formed?

1.  It is an endothermic reaction
2.  It is an exothermic reaction
3. The pH of the resulting solution will be more than seven
4. The pH of the resulting solution will be less than seven

Barium chloride on reacting with ammonium sulphate forms barium sulphate and ammonium chloride. Which of the following correctly represents the type of the reaction involved?

1. Displacement reaction
2. Precipitation reaction
3. Combination reaction
4. Double displacement reaction

Electrolysis of water is a decomposition reaction. The mole ratio of hydrogen and oxygen gases liberated during electrolysis of water is

Which of the following is(are) an endothermic process(es)?

1. Dilution of sulphuric acid
2. Sublimation of dry ice
3. Condensation of water vapours
4. Evaporation of water