#### 10th Standard Science English Medium Free Online Test 1 Mark Questions with Answer Key 2020 - 2021 Part - 1

10th Standard

Reg.No. :
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Science

Time : 00:35:00 Hrs
Total Marks : 35

Part A

35 x 1 = 35
1. If the Earth shrinks to 50% of its real radius its mass remaining the same, the weight of a body on the Earth will

(a)

decrease by 50%

(b)

increase by 50%

(c)

decrease by 25%

(d)

increase by 300%

2. The gravitational force between two objects becomes _______ when the masses of both objects are halved without altering the distance between them.

(a)

$\frac{f}{4}$

(b)

$\frac{f}{2}$

(c)

f

(d)

2f

3. The eye defect ‘presbyopia’ can be corrected by

(a)

convex lens

(b)

concave lens

(c)

convex mirror

(d)

Bi focal lenses

4. Kilowatt hour is the unit of

(a)

resistivity

(b)

conductivity

(c)

electrical energy

(d)

electrical power

5. If a sound wave travels with a frequency of 1.25 x 104 Hz 344 ms-1, the wavelength will be

(a)

27.52 m

(b)

275.2 m

(c)

0.02752 m

(d)

2.752 m

6. What is the frequency range of audible sound?

(a)

20 Hz to 20 kHz

(b)

1.5 Hz to 20 kHz

(c)

10 Hz to 15 kHz

(d)

20 Hz to 25 kHz

7. Kamini reactor is located at __________

(a)

Kalpakkam

(b)

Koodankulam

(c)

Mumbai

(d)

Rajasthan

8. Natural uranium consists of _________ % of U235 and _______ % of U238.

(a)

0.72,99.28

(b)

99.28,0.72

(c)

77.28,72

(d)

72, 77.28

9. The volume occupied by 1 mole of a diatomic gas at S.T.P is

(a)

11.2 litre

(b)

5.6 litre

(c)

22.4 litre

(d)

44.8 litre

10. In the alumino thermic process the role of Al is _____.

(a)

oxidizing agent

(b)

reducing agent

(c)

hydrogenating agent

(d)

sulphurising agent

11. The distance from the centre of the nucleus to the outer most electron in an ion is termed as _________ radii.

(a)

atomic

(b)

ionic

(c)

Covalent

(d)

both (b) and (c)

12. A 25% alcohol solution means

(a)

25 ml alcohol in 100 ml of water

(b)

25 ml alcohol in 25 ml of water

(c)

25 ml alcohol in 75 ml of water

(d)

75 ml alcohol in 25 ml of water

13. Which of the following represents a precipitation reaction?

(a)

A(s) + B(s) → C(s) + D(s)

(b)

A(s) + B(aq) → C(aq) + D(l)

(c)

A(aq) + B(aq) → C(s) + D(aq)

(d)

A(aq) + B(s) → C(aq) + D(l)

14. The product formed when calcium oxide reacts with water is

(a)

Slaked lime

(b)

Carbon dioxide

(c)

Calcium oxide

(d)

Oxygen gas

15. TFM in soaps represents ___________ content in soap

(a)

mineral

(b)

vitamin

(c)

fatty acid

(d)

carbohydrate

16. When ethanol reacts with acidified K2Cr2O7 the orange color of K2Cr2O7 changes to _____________

(a)

yellow

(b)

red

(c)

purple

(d)

green

17. The brain of leech lies above the

(a)

Mouth

(b)

Buccal Cavity

(c)

Pharynx

(d)

Crop

18. The wall of human heart is made of

(a)

Endocardium

(b)

Epicardium

(c)

Myocardium

(d)

All of the above

19. The _________are the largest ofleucocytes

(a)

neutrophil

(b)

monocyte

(c)

basophil

(d)

lymphocyte·

20. The neurons which carries impulse from the central nervous system to the muscle fibre.

(a)

afferent neurons

(b)

association neuron

(c)

efferent neuron

(d)

unipolar neuron

21. ______ is a growth inhibitor.

(a)

Auxin

(b)

GA

(c)

Cytokinin

(d)

Ethylene

22. Asexual reproduction takes place through budding in ___________

(a)

Amoeba

(b)

Yeast

(c)

Plasmodium

(d)

Bacteria

23. Pollination with the help of insects like honey bees, flies are called_________

(a)

Entomophilly

(b)

Anemophily

(c)

Hydrophily

(d)

Zoophily

24. Lack of menstruation generally indicates________

(a)

Pregnancy

(b)

Anemia

(c)

Amenorrhea

(d)

Over weight

25. The _____________ units form the backbone of the DNA.

(a)

5 carbon sugar

(b)

Phosphate

(c)

Nitrogenous bases

(d)

Sugar phosphate

26. Hydrogen bonds between the nitrogeneous bases make the DNA molecule________

(a)

unstable

(b)

stable

(c)

unbalanced

(d)

disturbed

27. Minerals like __________ slowly penetrate in and replace the original organic tissue and forms a rock like fossil.

(a)

calcium

(b)

sodium

(c)

magnesium

(d)

silica

28. Which of the following is used to produce products useful to humans by biotechnology techniques?

(a)

enzyme from organism

(b)

live organism

(c)

vitamins

(d)

both (a) and (b)

29. ________ is father of "Indian Green Revolution"

(a)

Dr. M. S. Swaminathan

(b)

Dr. Norman

(c)

Alec Jeffrey

(d)

Dr. Ian Wilmut

30. Coronary heart disease is due to

(a)

Streptococci bacteria

(b)

Inflammation of pericardium

(c)

Weakening of heart valves

(d)

Insufficient blood supply to heart muscles

31. World AIDS Day is observed on ______________

(a)

1st December

(b)

15th December

(c)

24th November

(d)

1st May

32. A cheap, conventional, commercial and inexhaustible source of energy is

(a)

hydropower

(b)

solar energy

(c)

wind energy

(d)

thermal energy

33. Wild life preservation society of India is located in_______

(a)

Delhi

(b)

Uttarakhand

(c)

(d)

Chattisgarh

34. In Scratch, the characters are known as_________

(a)

Sprite

(b)

Stage

(c)

Element

(d)

Script