### SAT - Science - Physics - Light

#### Question - 1

The teacher asked Alisha to perform an experiment on refraction of light using a glass slab. Alisha, being a smart girl. decided to make the light of a torch incident as parallel rays on the face ABas shown in the diagram.What would happen to the light?

• A The light will be completely reflected from the face AB
• B The light will spread as it enters the glass slab and will come out from faces BC and AD
• C The light will converge as it enters the slab and all the rays will meet at a point
• D the light will neither spread nor converage and come out of the face CD as parallel rays

#### Question - 2

To get three images of single object, one should have two plane mirrors at an angle of

• A 450
• B 600
• C 900
• D 1350

#### Question - 3

A rectangular block of glass (R.1 = 3/2) is kept in water (R.1=4/3). The critical angle for total internal reflection between glass and water is

• A Sin-1(2/3)
• B Sin-1(3/4)
• C Sin-1(8/9)
• D Sin-1(1/2)

#### Question - 4

A plane glass slab is kept over various coloured letters.The letters which appears least raised is

• A blue
• B violet
• C green
• D red

#### Question - 5

Total internal reflection can occur when light passes from

• A air to water
• B water to glass
• C air to glass
• D glass to water

#### Question - 6

A square wire of side 3.0 cm is placed 25 cm in front of a concave mirror of focal length 10 cm with its centre on the axis of the mirror and its plane normal to the axis. The area enclosed by the image of the wire is

• A 7.5 cm2
• B 6.0 cm2
• C 4.0 cm2
• D 3.0 cm2

#### Question - 7

For a concave mirror of focal length 20 cm, if the object at a distance of 30 em from the pole, then the nature of the image and magnification will be

• A real and - 2
• B virtual and - 2
• C real and +2
• D virtual and + 2

#### Question - 8

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

• A f1 + f2
• B $f_1 + f_2\over 2$
• C $f_1 f_2\over f_1 + f_2$
• D $\sqrt{f_1 f_2}$

#### Question - 9

The image of an object formed by a device is always virtual and small. The device may be

• A a glass plate
• B a concave mirror
• C a convex lens
• D a concave lens

#### Question - 10

A man standing in front of a concave spherical mirror of radius of curvature 120 cm sees an erect image of his face four times its natural size. Then the distance of the man from the mirror is

• A 180 cm
• B 300 cm
• C 240 cm
• D 45 cm