VIII SCIENCE

1.       Organic nutrients are called

(a)Fertilizers       (b) Manures       (c) Both a) and (b)           (d) None of these

2.       For safe storage of cereal grains, moisture content of the grain should not be more than

(a)84%                  (b)44%                  (c) 34%                                 (d) 14%

3.       Pasteurization of milk destroys its

(a)vitamins                         (b)fat contents (c) bacteria                         (d) None of these

4.       Carrier of malaria causing pathogen is

(a)House fly       (b)Cockroach     (c)Female Anophleses                   (d) None of these

5.       The raw material used for Teflon is

(a)ethene           (b)wood pulp    (c)ester                                (d)tetrafluoroethene

6.       The process by which artificial fibers are made is called

(a)Polymerisation            (b)plasticity        (c)elasticity                         (d)regeneration

7.       A superior synthetic fibre made by the polymerization of amide molecules obtained from petroleum is called:

(a)teflon              (b)nylon               (c) koroseal                        (d)rayon

8.       Which one of the following is a non-metal and good conductor of electricity

(a) zinc                  (b)lead (c) graphite                         (d)lithium

9.       Which among the following is not a noble gas

(a)helium                            (b)neon               (c)bromine                         (d)argon

10.   Which among the following is used in for making microchip for electronic goods

(a)sodium                           (b)sulpher           (c)silicon                              (d)phosphorus

11.   Which among the following is not a component of biodiversity?

(a)plant                                (b)animal             (c)microorganism                             (d)water

12.   Species which are restricted to a particular geographical region are called:

(a)endangered species (b)vulnerable species (c)endemic species  (d)wildlife

Sperms are produced by

(a)ovary (b)oviduct (c)testis  (d)uterus

13.   Which among the following is not a component of female sex organ?

  (a)uterus (b)oviduct (c)testis  (d)vagina

14.   Which among these is not a oviparous animal

(a)lizard (b)frog (c)lizard  (d)rat

15.   A car is heading towards south-east. The force of friction acting on the car is towards

(a)south-east (b)south-west (c)north-east  (d)north-west

16.   A cubical body has surfaces 5cm2, 20cm2,10cm2. Which surface will offer maximum frictional force

 (a)20 cm2 (b)10cm2 (c)5cm2  (d) all will offers same frictional force

17.   1kgf is equal to

(a)10 N (b)100 N (c)1000N  (d)none of these

18.   The force which exists between an electrically charged body and an uncharged body is:

(a)    electromotive force(b)electrostatic force (c)biological force  (d)magnetic force

19.   The practice of leaving the field uncultivated is called

20.   What are the two main crop seasons? Give three example of the crops grown during each season.

21.   What is crop rotation? Mention its advantages.

22.   Two diseases each caused by bacteria , fungi, protozoa and virus.

23.   What is vacnine? Who developed the first vaccine? How does it prevent us from the disease?

24.   What beneficial role do microorganism play in the life of human beings?