Two identical equiconvex thin lenses each of focal lengths 20 cm, made of material of refractive index 1.5 are placed coaxially in contact as shown. Now, the space between them is filled with a liquid of refractive index 1.5. The equivalent power of this arrangement will be:

1.  + 5D

2.  Zero

3.  + 2.5D

4.  + 0.5D

Subtopic:  Lensmakers' Formula |
To view explanation, please take trial in the course below.
NEET 2022 - Target Batch - Aryan Raj Singh

Difficulty Level:

The length of an astronomical telescope adjusted for parallel light is 90 cm. If the magnifying power of the telescope is 17, then the focal length of eyepiece and objective are respectively

1.  10 cm and 80 cm

2.  85 cm and 5 cm

3.  70 cm and 20 cm

4.  5 cm and 85 cm

Subtopic:  Telescope |
To view explanation, please take trial in the course below.
NEET 2022 - Target Batch - Aryan Raj Singh

Difficulty Level:

A ray of light falls on a transparent sphere as shown in the figure. If the final ray emerges from the sphere parallel to the horizontal diameter, then calculate the refractive index of the sphere. Consider that the sphere is kept in the air.

1.

2.

3.

4.  $\sqrt{4/3}$

Subtopic:  Refraction at Curved Surface |
To view explanation, please take trial in the course below.
NEET 2022 - Target Batch - Aryan Raj Singh

Difficulty Level:

Absolute refractive indices of glass and water are 3/2 and 4/3. The ratio of velocity of light in glass and water will be

1.  4:3

2.  8:7

3.  8:9

4.  3:4

Subtopic:  Refraction at Plane Surface |
To view explanation, please take trial in the course below.
NEET 2022 - Target Batch - Aryan Raj Singh

Difficulty Level:

A ray of light incident on an equilateral prism at grazing incidence emerges from the prism at grazing emergence. Refractive index of the prism is

1. 1.5

2. 1.8

3. 1.33

4. 2

Subtopic:  Prisms |
To view explanation, please take trial in the course below.
NEET 2022 - Target Batch - Aryan Raj Singh

Difficulty Level:

Which of the following is not due to the total internal reflection of light

1.  Brilliance of the diamond

2.  Mirage on hot summer days

3.  Working of optional fiber

4.  Difference between real and apparent depth of a pound

Subtopic:  Total Internal Reflection |
To view explanation, please take trial in the course below.
NEET 2022 - Target Batch - Aryan Raj Singh

Difficulty Level:

Assume that light of wavelength 7000 Angstrom is coming from a star. The limit of resolution (in radian) of a telescope whose objective has a diameter of 244 cm, will be

1.

2.

3.

4.

Subtopic:  Resolution of Optical Devices |
To view explanation, please take trial in the course below.
NEET 2022 - Target Batch - Aryan Raj Singh

Difficulty Level:

A point source of light B is placed at a distance L in front of the centre of a mirror of width d hung vertically on a wall. A man walks in front of the mirror along a line parallel to the mirror at a distance 2L from it as shown. The greatest distance over which he can see the image of the light source in the mirror is

(1) d/2

(2) d

(3) 2d

(4) 3d

Subtopic:  Reflection at Plane Surface |
To view explanation, please take trial in the course below.
NEET 2022 - Target Batch - Aryan Raj Singh

Difficulty Level:

Two plane mirrors, A and B are aligned parallel to each other, as shown in the figure. A light ray is incident at an angle of $30°$ at a point just inside one end of A. The plane of incidence coincides with the plane of the figure. The maximum number of times the ray undergoes reflections (excluding the first one) before it emerges out is :

1.  28

2.  30

3.  32

4.  34

Subtopic:  Reflection at Plane Surface |
To view explanation, please take trial in the course below.
NEET 2022 - Target Batch - Aryan Raj Singh

Difficulty Level:

A concave mirror of focal length 100 cm is used to obtain the image of the sun which subtends an angle of $30°$. The diameter of the image of the sun will be

(1)

(2) $0.87cm$

(3)

(4) 100 cm

Subtopic:  Reflection at Spherical Surface |
To view explanation, please take trial in the course below.
NEET 2022 - Target Batch - Aryan Raj Singh

Difficulty Level: