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Q1. Two thin lenses of power +3.5 D and –2.5 D are placed in contact. Find the focal length of the lens combination?

100 cm

1 cm

16.7cm

–16.7 cm

Q2. Two thin lenses of focal lengths f1 and f2 are placed adjacent to each other. What is the focal length of the combination?

f1 + f2

(f1 + f2)/2

f1f2/(f1 + f2)

f1+f2/f1f2

Q3. Two identical prisms are placed parallel to each other in upside down position with each other. What is the colour of the light coming out from the prisms?

Blue

Red

White

Green.

Q4. Two forces acting at right angles, which have the same effects as a single force is called

Components

Constituents

Resultants

Parallel.

Q5. Two conducting wires of same material and of equal lengths and equal diameters are first connected in series and than parallel in a circuit across the same potential difference. What is the ratio of· heat produced in series and parallel combinations?

1:2

2:1

1:4

4:1

Q6. Two bulbs of 100 w and 200 W have been connected in parallel with 220 V AC supply. Which bulb has more current to flow through?

100 w

200 w

Both have same current

Cannot say.

Q7. Two bulbs A and Bare connected in series with a cell having resistance of Ra and Rb. What is the ratio of electric potential difference across A and B?

Ra : Rb

1:1

Rb : Ra

Data insufficient

Q8. Two bodies with K.E in the ratio 4 : 1 are moving with equal linear momentum. What is the ratio of their mass?

1:1

4:1

1:4

1:2

Q9. Two bodies A and B of equal masses are kept at a height of hand 2h. What will be ratio of potential energy ?

1 : 2

0.0840277777777778

4: 1

0.0444444444444444

Q10. Two bobs of masses 1 kg and 2 kg are suspended from a rigid support by threads of lengths 4 m and 1 m. The ratio of their time period is

Q11. Two 100 W and 200 W bulbs are used at 220V. Find the amount of current drawn.

30/22

10/22

20/22

15/22

Q12. Transverse waves are produced in

Solids and liquids

Liquids and gases

Solids and gases

In all solid, liquid and gas

Q13. Transformer ratio is the ratio of ...........

Secondary voltage to the primary voltage

Primary voltage to the secondary voltage

Number of turns in the primary to ti1e number of turns in the secondary

Secondary current to the primary current.

Q14. Total number of electrons present in 4 A current flowing for 1 s is

2.5 × 1019

2.5 × 1020

1.25 × 1013

2.5 × 10–19

Q15. To which galaxy sun belongs?

Irregular

Elliptical

Spiral

None of these.

Q16. To start chain reaction which particle is used?

Fast moving neutrons

Slow moving neutrons

Slow moving protons

Fast moving protons

Q17. To see the lines on the palm of a human clearly, which lens is used by palmist?

Concave lens

Convex lens

Convex mirror

Concave mirror

Q18. To read the script which is not clearly visible for naked eye, which lens is preferred?

Convex lens of focal length 100 cm

Concave lens of focal length 50 cm

A concave lens of focal length of 75 cm

A convex lens of 3 cm.

Q19. To produce a pure spectrum, in what position the prism should be

Normal

Minimum deviation

Inverted

Deviation

Q20. To prevent the leakage of nuclear radiation, what is provided with the nuclear reactor?

Neutron reflector

Control rods

Moderator

Radiation shield.

Q21. To prevent the breeding of mosquitoes in rainy season

Phenol is added

Oil is sprayed

Alcohol is poured

Detergent is added

Q22. To prevent nuclear radiation, the reactor is usually surrounded by .......

Thick lead lining

Nickel lining

Iron lining

Cadmium lining.

Q23. To increase resistance, one should use combination of resistors in ...........

Series

Parallel

May be series

Should be in series

Q24. To minimize the power loss, the electric power should be transmitted at ...........

Low voltage and low current

High voltage and high current

Low voltage and high current

High voltage and low current.

Q25. To increase both the resolving power and magnifying power of a telescope.

Wavelength of light has to be decreased

Aperture of the objective to be increased

Increase the focal length of objective

Increase both focal length and aperture of the objective.

Q26. To increase both the resolving and magnifying power of a telescope .

Aperture of the objective has to be increased

Wavelength of light has to be decreased

Focal length of the objective has to be increased

Both the focal length and aperture of the objective has to be increased.

Q27. To get better observation of fluorescence, Roentgen covered the discharge tube with ...........

Black cloth

Black paper

Thin black card board

Black paint.

Q28. To get an image larger than the object one can use

A convex mirror but not concave

A concave mirror but not a convex

Either a convex or a concave mirror

Plane mirror

Q29. To get a real, inverted and diminished image between F and C, where should the object be placed?

Beyond C

At C

At F

Between F and P.

Q30. To avoid heat by radiation the calorimeter is electroplated with

Nickel

Silver

Copper

None of the above

Q31. To get a pure spectrum, the incident beam of light

Should be parallel

Converged

Should be brought to focus

Should be diverged.

Q32. Time taken by the sunlight to pass through a window of thickness 6 mm whose refractive index 1. 5 is

3 × l0–11 S

3 × 10–5 S

3 × 1011 S

3 × 108 S

Q33. Time taken by a freely falling body to reach the ground is 8 sec. What is the height from where it dropped?

78.4 m

313.6 m

31.36 m

3.136 m

Q34. Through which medium light propagates easily?

Opaque

Translucent

Transparent

Partially translucent.

Q35. There are two wires of same material and length. The diameter of the first wire is double the diameter of the second. What is the resistance of the second wire?

Half the resistance of the first wire

Double the resistance of the first wire

Equal to the resistance of first wire

Four times the resistance of the first wire.

Q36. There are three bulbs of 25, 40 and 60 W all operating at 220 V. Choose which one has the lowest resistance.

40 W

60 W

25 W

Data is not clear.

Q37. There are fundamentally ......... kinds of equilibrium

One

Two

Three

Four.

Q38. The working of an ink filler is an application of

Air pressure

Liquids pressure

Densities

None of the above.

Q39. The work function of a photo electric materials is 3.3 ev. The threshold frequency will be

8 × 1014 Hz

8 × 1010 Hz

5 × 1020 Hz

4 × 1014 Hz

Q40. The wind energy map gives information about the

‘Amount of rainfall

Causes of wind

Intensity of the earth quake

None of the above

Q41. The weight of a person is 600 N to climb a height of 10m, how much energy he requires?

6000J

60 J

58800J

None

Q42. The weakest force which dominates the universe is ..............

Strong nuclear force

Weak nuclear force

Electromagnetic

Gravitational

Q43. The wavelength range of IR rays is

6 × 10–7 m to 3.8 × 10–7 m

1 × 10–10 m to 3 × 10–8 m

3.8 × 10–7 m to 7.8 × 10–7 m

7.8 × 10–7 m to 3 × 10–5 m

Q44. The wavelength of the photons is proportional to

Q45. The wavelength range of EM wave is in order of

Few a km down to 10–14 m

Few a km down to 1014 m

10–14 km – few km

1014 km – few km

Q46. The wavelength 5 × 10–7m corresponds to

IR spectrum

X-ray spectrum

Visible spectrum

UV Spectrum.

Q47. The volatile liquid used in refrigerator is

Freon

Water

Helium

Acetane.

Q48. The viscous force is inversely proportional to

Area of the liquid

Relative velocity

Distance between the layers of liquid

Square of the distance between the layers.

Q49. The velocity of sound is maximum in

Water

Helium

Oil

Copper

Q50. The very low freezing mixture is made of

Ice and salt

Ice and KOH

Ice and Na

NaCl and wood.

Answers Evaluate

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