Choose The Correct Answer

Questions:-

1. The colour of sky is clear blue because of - 

(a) Diffraction of light

(b) Dispersion of light

(c) Reflection of light

(d) Refraction of light.

2. The direction of current in a Diode is— 

(a) filament to cathode

(b) Plate to Battery

(c) Cell to plate

(d) Plate to cathode.

3. Static friction is -

(a) Always less than dynamic friction

(b) Equal to the dynamic friction

(c) Greater than dynamic friction

4. Newton's law of gravitation applies to 

(a) On small bodies.

(b) On planets.

(c) Any body, small or big

(d) Within the solar system only.

5. Through what media sound travels fastest.

(a) Cool air 

(b) Hot air

(c) Water 

(d) Metal

6. Which color light has the longest wave length

(a) Purple

(b) Pink

(c) Grey

(d) Red

7. In electric bulbs, which mixture of gases is used

(a) Oxygen and hydrogen

(b) Oxygen and argon

(c) Nitrogen and Oxygen

(d) Hydrogen and Argon

8. The filament of the bulb is made up of

(a) Tungsten 

(b) Aluminium

(c) Copper 

(d) Alloy of copper and nickel.

9. In what unit magnetic intensity is expressed?

(a) coulomb 

(b) gauss

(c) Oersted 

(d) volt

10. Out of the following fuels, which is used in the modern submarines-

(a) nuclear fuel 

(b) petrol

(c) coal

(d) nitrogen

11. An ice cube floats on water but sinks in Alcohal why?

(a) ice cube is solidified form of water,

(b) ice cube is a solid and Alcohal is a liquid.

(c) ice cube is lighter than water and heavier than alcohal

12. Which of the following are emitted by the filament of a vacuum tube?

(a) electrons 

(b) neutrons

(c) protons 

(d) none of them

13. At poles an object weighs less at the equator, because-

(a) gravitational force is more at the equator than at poles 

(b) gravitational force is less at the equator

(c) earth is more flater at the equator

(d) radious of the earth at equator is less than that at poles.

14. What instrument is used to detect electric charge?-

(a) electroscope 

(b) galvanometer

(c) ammeter 

(d) voltmeter

15. Which is the common constituent of transistors ?

(a) Berylium 

(b) Copper

(c) Germanium 

(d) steel

16. Fuse wire used in electric circuit is made of material having -

(a) high resistance

(b) low specific heat

(c)low melting point

(d) low resistance

17. What force hold together protons and neutrons in the nucleus of an atom -

(a)frictional 

(b)gravitational

(c) magnetic 

(d) nuclear

18. Why is that water boils at lower temperature than 100 degree centigrade at higher altitudes?

(a) It is pollution free.

(b) Atmospheric pressure is low.

(c) Lesser dissipation of heat as compared to sea level.

19. Pytheliometer is used for-

(a) comparing luminous flux

(b) to measure solar radiation

(c) measuring temperature

(d) to measure thermal radiations. 

20. The sun spectrum is-

(a) line spectrum (b) band spectrum

(c) continuous spectrum (d) none of these

21. The rod in a dry cell is made of

(a) Carbon 

(b) Copper

(c) Zinc 

(d) Iron

22. What is the purpose of using an Electric Transformer

(a) Conversion of A C to D C

(b) To regulate fluctuation of voltage

(c) Conversion of low voltage to high andviceversa

23. The branch of physics which deals with measurement of light is known as

(a) Photometery 

(b) Spectrometery

(c) Spectroscopy

24. In a Camera fitted with a convex lens the image formed will be -

(a) Inverted and real 

(b) Real and Erect

(c) Imagenary & erect

(d) Depends on the distance of the object

25. As the temperature of water increases the surface tension—

(a) Increases 

(b) Decreases

(c) Remains same 

26. Roentgen rays were discovered by-

(a) Charles Darwin

(b) Watson

(c) C.V.Raman

(d) Wilhelm Roentgen.

Answers :- 

1.(b) Dispersion of light.

2.(d) Plate to cathode.

3.(b) Equal to the dynamic friction.

4.(c) Any body , small or big.

5.(d) Metal.

6.(d) Red.

7.(b) Oxygen and argon.

8.(a) Tungsten.

9.(c) Oersted.

10.(a) Nuclear fuel.

11.(c) Ice cube is lighter than water and heavier than alcohol

12.(a) Electrons

13.(b) gravitational force is less at the equator

14.(a) Electroscope.

15.(c) Germanium.

16.(c) low melting point

17.(d) nuclear.

18.(b) Atmospheric pressure is low.

19.(b) To measure solar radiation.

20.(c) Continuous spectrum.

21.(a) Carbon.

22.(c) Conversion of low voltage to high and vice-versa.

23.(a) Photometery.

24.(a) Inverted and real.

25.(b) Decreases

26.(d) Wilhelm Roentgen.