MCQs of Ray Optics & Optical Instruments

Ray Optics & Optical Instruments MCQs

MCQs of Ray Optics & Optical Instruments

Showing 131 to 140 out of 143 Questions

131.

For a thin lens when the heights of the object and the image are equal, object distance and image distance are equal to _____ .

(a)	f
(b)	4f
(c)	3f
(d)	2f

132.

Two converging lenses of powers 5D and 4D are placed 5 cm apart. Find the focal length and power of this combination.

(a)	12.5 cm, 4 D
(b)	12.5 cm, 8 D
(c)	25 m, 8 D
(d)	25 m, 4D

133.

For a prism, angle of prism is 60° and it's refractive index is 1.5, find (1) angle of incidence corresponding to the angle of minimum deviation and (2) angle of emergence for angle of maximum deviation.

(a)	48° 35' , 27.9°
(b)	90° , 27.31°
(c)	43° 85' , 29.7°
(d)	45° 35' , 25.9°

134.

An equilateral prism is kept in air and for a particular ray, angle of minimum deviation is 38°. If the prism is immersed in water, the angle of minimum deviation = _____ Refractive index of water is 1.33.

(a)	9° 12'
(b)	9.8°
(c)	9° 25'
(d)	9.5°

135.

An object is 10 mm from the objective of a compound microscope. The lenses are 30 cm apart and the intermediate image is 50 mm from the eyepiece. Overall magnification is produced by the instrument = _____ .

(a)	177.14
(b)	124.0
(c)	464.0
(d)	77.5

136.

An object moves with uniform velocity (v₀) on the axis of a concave mirror. If it moves towards the mirror, show that when it is at a distance u from the mirror, the velocity of its image is given by v_i = _____ , (where R is radius of curvature of the mirror.)

(a)	${(\frac{R}{2 u - R})}^{2} \cdot v_{0}$
(b)	${(\frac{R}{R - 2 u})}^{2} \cdot v_{0}$
(c)	$- {(\frac{R}{2 u - R})}^{2} \cdot v_{0}$
(d)	${(\frac{2 u - R}{R})}^{2} \cdot v_{0}$

137.

An image of a linear object due to a convex mirror is

\frac{1}{4}

th of the length of the object. If focal length of the mirror is 10 cm, the distance between the object and the image = _____ . The linear object is kept perpendicular to the axis of mirror.

(a)	22.5 cm
(b)	-22.5 cm
(c)	40 cm
(d)	37.5 cm

138.

The diameter of the sun subtends an angle of 0.5° at the pole of the concave mirror. The radius of curvature of the mirror is 1.5 m. Find the diameter of the image of the sun. (Consider the distance of sun from the mirror infinite.)

(a)	0.6525 cm
(b)	0.6525 m
(c)	65.25 mm
(d)	6.525 m

139.

A narrow beam of light is incident on a glass plate of refractive index 1.6. It makes an angle 53° with normal to the interface. Find the lateral shift of the beam at the point of emergence, if thickness of the plate is 20 mm. (Take sin53° = 0.8.)

(a)	9.0 mm
(b)	9.0 cm
(c)	90 mm
(d)	0.9 mm

140.

A real image obtained by a concave mirror is 4 times bigger than the object. If the object is displaced by 3 cm away from the mirror, the image size becomes 3 times the object size. The focal length of the mirror = _____ .

(a)	360 mm
(b)	3.6 cm
(c)	36 mm
(d)	3.6 mm

Showing 131 to 140 out of 143 Questions