English Medium कक्षा १० - CBSE Question Bank Solutions for Science

When do we consider a student sitting in the class to be myopic? List two causes of this defect. Explain using a ray diagram how this defect of eye can be corrected.

The near point of the eye of a person is 50 cm. Find the nature and power of the corrective lens required by the person to enable him to see clearly the objects placed at 25 cm from the eye?

Solve the following question:
The near point of the eye of a person is 50 cm. Find the nature and power of the corrective lens required by the person to enable him to see clearly the objects placed at 25 cm from the eye?

Draw a ray diagram to show the formation of the image, when the object is placed between optical centre and principal focus of a convex lens.

State the signs and values of magnifications in the above mentioned case.

Answer the following question.
Write the modification in the curvature of the eye lens which enables us to see the nearby objects clearly?

A person is unable to see objects distinctly placed within 50 cm from his eyes.

(a) Name the defect of vision the person is suffering from and list its two possible causes.

(b) Draw a ray diagram to show the defect in the above case.

(c) Mention the type of lens used by him for the correction of the defect and calculate its power. Assume that the near point for the normal eye is 25 cm.

(d) Draw a labeled diagram for the correction of the defect in the above case.

A teacher gave two test tubes to the students, one containing water and the other containing sodium hydroxide. She asked them to identify the test tube containing sodium hydroxide solution. Which one of the following can be used for identification?

Which of the following is true for an unbalanced chemical equation?

Which of the following is Not True with respect to the neutralisation reaction?

Before burning in air, the magnesium ribbon is cleaned by rubbing with sand paper to:

In a chemical reaction between sulphuric acid and barium chloride solution the white precipitates formed are of:

A chemical reaction does not involve:

It is necessary to balance a chemical equation in order to satisfy the law of:

When ferrous sulphate is heated strongly it undergoes decomposition to form ferric oxide as a main product accompanied by a change in colour from:

Magnesium ribbon is rubbed before burning because it has a coating of ____________.

Name the products formed when iron filings are heated with dilute hydrochloric acid.

Myopia and hypermetropia can be corrected by:

In torches, search lights and headlights of vehicles the bulb is placed ______.

A person cannot see distinctly objects kept beyond 2 m. This defect can be corrected by using a lens of power:

Assertion: Myopia is the defect of vision in which a person cannot see distant objects clearly.

Reason: This due to eye-ball being too short.