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WorksheetsReflection and refraction of light
Total questions: 55
Worksheet time: 3hrs 45mins
The image formed by a plane mirror is:
Virtual, behind the mirror and enlarged
Virtual, behind the mirror and of the same size as the object
Real, at the surface of the mirror and enlarged
Real, behind the mirror and of the same size as the object
The angle between an incident ray and the plane mirror is 30°. The total angle between the incident ray and reflected ray will be:
30°
60°
90°
120°
A ray of light is incident on a plane mirror making an angle of 90° with the mirror surface. The angle of reflection for this ray of light will be:
45°
90°
0°
60°
In a convex spherical mirror, reflection of light takes place at
A flat surface
A bent-in surface
A bulging-out surface
An uneven surface
If R is the radius of curvature of a spherical mirror and f is its focal length, then what is the relation between them
R=f
R=2f
R=f/2
R=1/f
If the focal length of a spherical mirror is 12.5 less cm, its radius of curvature will be
25 cm
15 cm
20 cm
35 cm
The real image formed by a concave mirror is larger than the object when the object is
At a distance equal to radius of curvature
At a distance greater than radius of curvature
At focus and centre of curvature
At a distance less than focal length
The image formed by a concave mirror is virtual, erect and magnified. The position of object is
At focus
At pole
Between centre of curvature and focus
Between pole and focus
The image formed by a concave mirror is real, inverted and highly diminished. The object must be
Between center of curvature and focus
At centre of curvature
At focus
At infinity
The angle of incidence for a ray of light passing through the centre of curvature of concave mirror is
45°
90°
0°
180°
In the concave reflector of a torch, the bulb is placed
Between the pole and focus of reflector
At the focus of reflector
Between focus and centre of curvature of reflector
At the centre of curvature of reflector
The focal length of a small cancave mirror is 2.5 cm. In order to use this concave mirror as a dentist's mirror, the distance of tooth from the mirror should be
2.5 cm
1.5 cm
4.5 cm
3.5 cm
According to new Cartesian sign convention
Focal length of concave mirror is positive and that of convex mirror is negative
Focal length of both concave and convex mirror is positive
Focal length of both concave and convex mirror is negative
Focal length of concave mirror is negative and that of convex mirror is positive
One of the following does not apply to a concave mirror
Focal length is negative
Image distance can be positive or negative
Image distance is always positive
Height of image can be positive or negative
Which of following is the correct mirror formula
1/v - 1/u = 1/f
1/u - 1/v = 1/f
1/u + 1/v = 1/f
1/v + 1/u = 1/f
Linear magnification produced by a concave mirror may be
Less than 1 or equal to 1
More than 1 or equal to 1
Less than 1, more than 1 or equal to 1
Less than 1 or more than 1
Which of the following can make a parallel beam of light when light from a point source is incident on it?
Concave mirror as well as convex lens
Convex mirror as well as concave lens
Two plane mirrors placed at 90° to each other
Concave mirror as well as concave lens
A 10 mm long awl pin is placed vertically in front of a concave mirror. A 5 mm long image of the awl pin is formed at 30 cm in front of the mirror. The focal length of this mirror is
-30 cm
-20 cm
-40 cm
-60 cm
The diagrams showing the correct path of the ray after passing through the
II & III only
I & II only
I, II & III
I, II & IV
A light ray enters from medium A to medium B as shown in figure. The refractive index of medium B relative to A will be
Greater than unity
Less than unity
Equal to unity
Zero
Beams of light are incident through the holes A and B and emerge out of box through the holes C and D respectively as shown in the figure. Which of the following could be inside the box?
A rectangular glass slab
A concave lens
A convex lens
A prism
Magnification produced by a rear view mirror fitted in vehicles
is less than one
is more than one
is equal to one
can be more than or less than one depending upon the position of the object in front of it.
Magnification produced by a plane mirror is
Less than 1
More than 1
Equal to 1
Zero
If a magnification of -1 is to be obtained by using a converging mirror, then the object has to be placed
Between pole and focus
At the centre of curvature
Beyond the centre of curvature
At infinity
an object is placed at large distance in front of a concave mirror of radius of curvature 40cm. The image will be formed in front of the mirror at a distance of
20 cm
30 cm
40 cm
50 cm
The speed of light in air
3×10⁸ cm/sec
3×10⁸ m/sec
2.9970 ×10⁸ m/sec
Both ii and iii
Which of the following diagrams shows the ray of light reflected correctly?
A only
A, B and C
C and D
E only
The reactive indices of four substances P, Q, R and S are 1.50, 1.36, 1.77 and 1.31 respectively. The speed of light is the maximum in the substance
P
Q
R
S
The refractive index of glass for light going from air to glass is 3/2. The refractive index for light going from glass to air will be:
1/3
6/4
3/2
4/6
The refractive index of water with respect to air is 4/3. The refractive index of air with respect to water will be
1.75
0.50
0.75
0.25
You are given water, mustard oil, glycerine and kerosene. In which of these media a ray of light incident obliquely at same angle would bend the most?
Water
Mustard oil
Glycerine
Kerosene
A child is standing in front of a magic mirror. She finds the image of her head bigger, the middle portion of her body of the same size and that of the legs smaller. The following is the order of combinations for the magic mirror from the top.
Plane, convex and concave
Convex, concave and plane
Concave, plane and convex
Convex, plane and concave
Light travel fastest in
Air
Vaccum
Water
Glass
A student used a device (X) to obtain/focus the image of a well illuminated distant building on a screen (S) as shown alongside in the diagram. Select the correct statement about the device (X).
This device is a concave lens of focal length 8 cm.
This device is a convex mirror of focal length 8 cm.
This device is a convex lens of focal length 4 cm.
This device is a convex lens of focal length 8 cm.
A lens of focal length 12 cm forms an erect image, three times the size of the object. The distance between the object and image is:
8 cm
16 cm
24 cm
36 cm
Focal length of plane mirror is
At infinity
Zero
Negative
None of these
The unit of power of lens is
Meter
Centimeter
Diopter
M-1
In order to obtain a real image twice the size of the object with a convex lens of focal length 15 cm, the object distance should be
More than 5 cm but less than 10 cm
More than 10 cm but less than 15 cm
More than 15 cm but less than 30 cm
More than 30 cm but less than 60 cm
A converging lens is used to produce an image of an a screen. What change is needed for the image to be formed nearer to the lens
Increase the focal length of the lens
Insert a diverging lens between the lens and the screen
Increase the distance of the object from the lens
Move the object closer to the lens
If the spherical lens has a power of -0.25 D, the focal length of this lens will be
-4 cm
-400 mm
-4 m
-40 m
One dioptre is the power of lens whose focal length is
1 m
1 cm
1 mm
1 dm
The focal length of four convex lenses P, Q, R and S are 20 cm, 15 cm, 5 cm and 10 cm respectively. The lens having greatest power is
P
Q
R
S
The optical phenomena, twinkling of stars, is due to
Atmospheric reflection
Total reflection
Atmospheric refraction
Total refraction
Power of the lens is -40, its focal length is
4 m
-40 m
-0.25 m
-25 m
Assertion (A) : A ray passing through the centre of curvature of a concave mirror after reflection, is reflected back along the same path.
Reason (R) : The incident rays fall on the mirror along the normal to the reflecting surface.
A and R are true and R is the correct explanation of A
A and R are true but R is not the correct explanation of A
A is true but R is false
A is false but R is true
Assertion (A) : Light does not travel in the same direction in all the media.
Reason (R) : The speed of light does not change as it enters from one transparent medium to another
A and R are true and R is the correct explanation of A
A and R are true but R is not the correct explanation of A
A is true but R is false
A is false but R is true
Assertion(A) : The emergent ray is parallel to the direction of the incident ray.
Reason (R) : The extent of bending of the ray of light at the opposite parallel faces (air- glass interface and glass-air interface) of the rectangular glass slab is equal and opposite.
A and R are true and R is the correct explanation of A
A and R are true but R is not the correct explanation of A
A is true but R is false
A is false but R is true
Assertion(A) : For observing traffic at back, the driver mirror is convex mirror.
Reason (R) : A convex mirror has much larger field of view than a plane mirror.
A and R are true and R is the correct explanation of A
A and R are true but R is not the correct explanation of A
A is true but R is false
A is false but R is true
Assertion(A) : Mirror formula can be applied to a plane mirror.
Reason (R) : A plane mirror is a spherical mirror of infinite focal length.
A and R are true and R is the correct explanation of A
A and R are true but R is not the correct explanation of A
A is true but R is false
A is false but R is true
Assertion(A) : It is not possible to see a virtual image by eye.
Reason (R): The rays that seem to emanate from a virtual image do not in fact emanates from the image.
A and R are true and R is the correct explanation of A
A and R are true but R is not the correct explanation of A
A is true but R is false
A is false but R is true
Assertion(A) : Concave mirrors are used as make-up mirrors.
Reason (R) : When the face is held within the focus of a concave mirror, then a diminished image of the face is seen in the concave mirror.
A and R are true and R is the correct explanation of A
A and R are true but R is not the correct explanation of A
A is true but R is false
A is false but R is true
Assertion(A): A person cannot see his image in a concave mirror, unless, he is standing beyond the center of curvature of the mirror.
Reason (R) : In a concave mirror, image formed is real provided the object is situated beyond its focus.
A and R are true and R is the correct explanation of A
A and R are true but R is not the correct explanation of A
A is true but R is false
A is false but R is true
A beam of light is incident through the holes on side A and emerges out of the holes on the other face of the box as shown in Figure. Which of the following could be inside the box?
Concave lens
Convex lens
Prism
Rectangular glass slab
The speed of light in air is 3 x 108 m s-1. Calculate the speed of light in glass. The refractive index of glass is 1.5
2×10⁸ m/sec
2.50×10⁸ m/sec
2.25×10⁸ m/sec
1.5×10⁸ m/sec
The Snell's laws of refraction are:
The incident ray, the refracted ray and the normal at the point of incidence, all lie in the same plane.
The ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant for the pair of the given media
Refractive index= sin i/sin r
All of the above
