IMPORTANT QUESTIONS

1. Q401 List two advantages using condom during act.

   Easy View solution
2. Q402 3 mL of ethanol is taken in a test tube and warmed gently in a water bath. A 5% solution of alkaline potassium permanganate is added first drop by drop to this solution, then in excess. How is 5% solution of KMnO₄ prepared?

   Medium View solution
3. Q403 Incomplete combustion of coal and petroleum: (A) increases air pollution. (B) increases efficiency of machines. (C) reduces global warming (D) produce poisonous gases. The correct option is:

   • (a)(A) and (B)
   • (b)(A)) and (D)
   • (c) (B) and (C)
   • (d)(C) and (D)

   Easy View solution
4. Q404 When hydrogen sulphide gas is passed through a blue solution of copper sulphate, a black precipitate of copper sulphide is obtained and the sulphuric acid so formed remains in the solution. The reaction is an example of a

   • (a)Combination reaction
   • (b) Displacement reaction
   • (c) Decomposition reaction
   • (d)Double displacement reaction

   Easy View solution
5. Q405 A small amount quick lime is added to water in a beaker. Name define the type of reaction that has taken place.

   Easy View solution
6. Q406 Ozone layer depletion may cause

   • (a)Skin cancer
   • (b)Genetic abnormally
   • (c)Blood cancer
   • (d) All

   Easy View solution
7. Q407 What is geographical isolation ?

   Easy View solution
8. Q408 What is heredity?

   Easy View solution
9. Q409 Which device produces the electric current?

   • (a)Generator
   • (b)Galvanometer
   • (c)Ammeter
   • (d)Motors

   Easy View solution
10. Q410 Where an object should be placed in front of a convex lens to get a real image of the size of the object?

    • (a)At the principal focus of the lens
    • (b)At twice the focal length
    • (c)At infinity
    • (d)Between the optical centre of the lens and its principal focus

    Easy View solution