English Medium Class 10 - CBSE Question Bank Solutions for Science

List three common refractive defects of vision. Suggest the way of correcting these defects.

About 45 lac people in the developing countries are suffering from corneal blindness. About 30 lac children below the age of 12 years suffering from this defect can be cured by replacing the defective cornea with the cornea of a donated eye. How and why can students of your age involve themselves to create awareness about this fact among people?

Write the balanced equation for the following chemical reaction.

\[\ce{Hydrogen + Chlorine -> Hydrogen chloride}\]

Write a balanced chemical equation with state symbols for the following reaction.

Solutions of barium chloride and sodium sulphate in water react to give insoluble barium sulphate and the solution of sodium chloride.

What type of oxides are formed when non-metals combine with oxygen?

A person with a myopic eye cannot see objects beyond 1.2 m distinctly. What should be the type of the corrective lens used to restore proper vision?

What is the far point and near point of the human eye with normal vision?

The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?

A student suffering from myopia is not able to see distinctly the objects placed beyond 5 m. List two possible reasons due to which this defect of vision may have arisen. With the help of ray diagrams, explain

(i) why the student is unable to see distinctly the objects placed beyond 5 m from his eyes.

(ii) the type  of the corrective lens used to restore proper vision and how this defect is corrected by the use of this lens.

(b) If, in this case, the numerical value of the focal length of the corrective lens is 5 m, find the power of the lens as per the new Cartesian sign convention

A student is unable to see clearly the words written on the black board placed at a distance of approximately 3 m from him. Name the defect of vision the boy is suffering from. State the possible causes of this defect and explain the method of correcting it.

A ray of light is incident on a plane mirror at an angle of 30°. What is the angle of reflection

A ray of light strikes a plane mirror at an angle of 40° to the mirror surface. What will be the angle of reflection?

A ray of light is incident normally on a plane mirror. What will be the 

angle of incidence?

A ray of light is incident normally on a plane mirror. What will be the 

 angle of reflection?

What type of image is formed: 

 in a plane mirror?

What type of image is formed: 

on a cinema screen?

What kind of mirror is required for obtaining a virtual image of the same size as the object?

What is the name of the phenomenon in which the right side of an object appears to be the left side of the image in a plane mirror?

The letter F is placed in front of a plane mirror: