cbse previous year question paper

Sign Up

Sign In

Forgot Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

You must login to ask question.

Ask A Question

Mayur Arya

Asked: December 23, 2023In: Class 10 Science

Both a spherical mirror and a thin spherical lens have a focal length of (-)15 cm. What type of mirror and lens are these?

Spherical lenses and mirrors have curved surfaces. Lenses can be converging (convex) or diverging (concave), affecting light focus. Mirrors, concave or convex, influence reflection properties, used in optics for various applications.

Mayur Arya

Asked: December 23, 2023In: Class 10 Science

Identify the products formed when 1 mL of dil. Hydrochloric acid is added to 1g of Sodium metal.

Sodium is a highly reactive alkali metal with atomic number 11. It’s silver-white, soft, and abundant in nature. It reacts vigorously with water, producing sodium hydroxide and hydrogen gas.

Mayur Arya

Asked: December 23, 2023In: Class 10 Science

Write the chemical name and chemical formula of the salt used to remove permanent hardness of water.

Water hardness is a measure of the concentration of calcium and magnesium ions. It affects soap effectiveness and can lead to scale buildup. Hard water is classified as temporary or permanent.