+91-8527521718
Signup | Login
Select Question Set:
filter
Q. No.

A parallel beam of light of intensity \(I_0\) is incident on a lens and the intensity of the emerging beam is \(4I_0\) after it has traversed a further distance of \(30\) cm from the lens. The focal length of the lens is:
1. \(40\) cm
2. \(20\) cm
3. \(45\) cm
4. \(60\) cm

Subtopic:  Lenses |
 53%
Level 3: 35%-60%

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.

A parallel beam is incident on to a lens of focal length \(f\) (positive), parallel to its principal axis. A thin prism of vertex angle \(A\) and refractive index \(\mu\) is inserted in the path of the parallel beam before it falls on the lens. The focal point of the image:
1. remains unchanged
2. is displaced along \(+y\) by \((\mu-1)Af\)
3. is displaced along \(-y\) by \((\mu-1)Af\)
4. is displaced along \(+x\) by \((\mu-1)Af\)
Subtopic:  Prisms |
Level 3: 35%-60%

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.

A point object \((A)\) is placed on the principal axis of a convex lens (focal length = \(30~\text{cm}\)) at a distance of \(45~\text{cm}\) from it. The image is formed at position \(B.\) If the object \(A\) is moved up by \(1~\text{cm}\) then the image moves:
         
1. down by \(1~\text{cm}\)
2. down by \(2~\text{cm}\)
3. up by \(1~\text{cm}\)
4. up by ​​​​​​​\(2~\text{cm}\)
Subtopic:  Lenses |
 65%
Level 2: 60%+

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.

advertisementadvertisement
An incident ray falling at an angle of \(30^\circ\) with the \(x\)-axis is reflected by a mirror to a (reflected) ray making \(60^\circ\) with the \(x\)-axis. The angle made by the mirror's surface (not shown in the diagram) with the \(x\)-axis is:
            
1. \(15^\circ\)
2. \(45^\circ\)
3. \(75^\circ\)
4. \(105^\circ\)
Subtopic:  Reflection at Plane Surface |
 64%
Level 2: 60%+

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.

A ray of light falling on a \(2^\circ\)-prism (thin prism) undergoes a \(3^\circ\)-deviation on the first surface and no deviation on the second. The refractive index of the material of the prism is:
1. \(1.5\)
2. \(1.75\)
3. \(2.0\)
4. \(2.5\)
Subtopic:  Prisms |
 75%
Level 2: 60%+

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.

premium feature crown icon
Unlock IMPORTANT QUESTION
This question was bookmarked by 5 NEET 2025 toppers during their NEETprep journey. Get Target Batch to see this question.
✨ Perfect for quick revision & accuracy boost
Buy Target Batch
Access all premium questions instantly
A ray of light \((1)\) gets reflected partially at the front surface of a thin film of thickness \(t,\) and refractive index \(\mu.\) The reflected ray from the front surface is \(2\) while that emerging due to reflection from the rear surface is \(3.\) Assume that ray \(1\) is incident normally. The optical path difference between rays \(2\) and \(3\) is:
1. \((\mu-1)t\) 2. \(2(\mu-1)t\)
3. \(\mu t\) 4. \(2\mu t\)
Subtopic:  Refraction at Plane Surface |
Level 4: Below 35%

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.

advertisementadvertisement
If two convex lenses of powers \(P_1,P_2\) be placed close together, co-axially, the combination behaves as a lens of power:
1. \(P_1+P_2\) 2. \(|P_1-P_2|\)
3. \({\Large\frac{P^2_1}{P_2}}\) 4. \({\Large\frac{P^2_2}{P_1}}\)
Subtopic:  Lenses |
 88%
Level 1: 80%+

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.

Two convex lenses \((L_1,~L_2) \) of focal lengths, \(20\text{ cm}\) \((L_1) \) and \(40\text{ cm}\) \((L_2),\) are placed co-axially at a separation of \(60\text{ cm}.\) If a parallel beam of light is incident on \(L_1, \) the emerging beam from \(L_2 :\)
1. is parallel but wider.
2. is parallel but narrower.
3. is convergent.
4. is divergent.
Subtopic:  Refraction at Curved Surface |
 56%
Level 3: 35%-60%

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.

A ray is incident normally onto the surface \(AB\) of the prism \((\angle A=30^\circ,\angle B=90^\circ).\) The refractive index of the material of the prism is \(\sqrt2.\) The deviation of this ray is:
   
1. \(30^\circ\) downward
2. \(15^\circ\) downward
3. \(30^\circ\) upward
4. \(15^\circ\) upward
Subtopic:  Prisms |
 69%
Level 2: 60%+

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.

advertisementadvertisement
A parallel beam of light is incident onto a converging lens \((L_1)\) of focal length \(20~\text{cm}.\) A second identical lens \((L_2)\) is to be placed behind \(L_1,\) coaxially, so that the emerging beam is parallel. The distance between \(L_1\) and \(L_2\) should be:
1. \(10\) cm 2. \(20\) cm
3. \(40\) cm 4. zero
Subtopic:  Lenses |
 77%
Level 2: 60%+

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.

Select Question Set:
filter
Q. No.

NEET Information

courses

Company

Botany Questions

Chemistry Questions

Physics Questions

Zoology Questions

© 2026 GoodEd Technologies Pvt. Ltd.