✅ True or False (10 Questions)

(CBSE Class 8 Standard | Good Quality)

1. A concave mirror has its reflecting surface curved inward.
   True hecu110
2. A convex mirror always forms an erect and diminished image.
   True hecu110
3. A plane mirror always forms an image smaller than the object.
   False
   (Plane mirror forms an image of the same size.) hecu110
4. In a concave mirror, the image can be erect or inverted depending on object distance.
   True hecu110
5. Convex mirrors are used as side-view mirrors in vehicles because they provide a wider view.
   True hecu110
6. The angle of incidence is always greater than the angle of reflection.
   False
   (They are equal according to the law of reflection.) hecu110
7. The incident ray, reflected ray, and normal lie in the same plane.
   True hecu110
8. A convex lens is thicker at the edges than at the centre.
   False
   (Convex lens is thicker at the centre.) hecu110
9. A concave lens always forms an erect and diminished image.
   True hecu110
10. Concave mirrors converge parallel rays of light after reflection.
    True

✅ Fill in the Blanks (10 Questions)

(CBSE Class 8 Standard | Good Quality)

1. A mirror with its reflecting surface curved inward is called a __________ mirror.
   Answer: concave hecu110
2. A mirror with its reflecting surface bulging outward is called a __________ mirror.
   Answer: convex hecu110
3. The point where parallel rays meet after reflection from a concave mirror is called the __________.
   Answer: focus hecu110
4. The distance between the pole and the focus of a spherical mirror is called the __________ length.
   Answer: focal hecu110
5. Convex mirrors are used in vehicles because they provide a __________ field of view.
   Answer: wider hecu110
6. The angle between the incident ray and the normal is called the angle of __________.
   Answer: incidence hecu110
7. According to the law of reflection, the angle of incidence is equal to the angle of __________.
   Answer: reflection hecu110
8. A convex lens is thicker at the __________ than at the edges.
   Answer: centre hecu110
9. A concave lens always forms a __________ and diminished image.
   Answer: erect hecu110
10. Lenses are transparent materials that refract __________.
    Answer: light

✅ Multiple Choice Questions (15 MCQs)

(CBSE Class 8 Standard | Good Quality)

1. A concave mirror is also called a:

A. Diverging mirror
B. Converging mirror
C. Plane mirror
D. Transparent mirror
✅ Answer: B hecu110

2. A convex mirror always forms an image that is:

A. Real and inverted
B. Virtual and enlarged
C. Virtual, erect and diminished
D. Real and diminished
✅ Answer: C hecu110

3. The point at the centre of a spherical mirror is called:

A. Focus
B. Centre of curvature
C. Pole
D. Radius
✅ Answer: C hecu110

4. The distance between pole and focus is known as:

A. Radius of curvature
B. Focal length
C. Diameter
D. Principal axis
✅ Answer: B hecu110

5. A concave mirror is used by dentists because it:

A. Gives a diminished image
B. Gives an enlarged image of teeth
C. Gives an inverted image
D. Has no reflection
✅ Answer: B hecu110

6. Side-view mirrors in vehicles are generally:

A. Plane mirrors
B. Concave mirrors
C. Convex mirrors
D. Lenses
✅ Answer: C hecu110

7. Convex mirrors are preferred in vehicles because they:

A. Form real images
B. Provide a wider field of view
C. Produce enlarged images
D. Absorb light rays
✅ Answer: B hecu110

8. The angle between incident ray and normal is called:

A. Angle of reflection
B. Angle of incidence
C. Angle of deviation
D. Angle of curvature
✅ Answer: B hecu110

9. According to the law of reflection:

A. Angle of incidence > angle of reflection
B. Angle of incidence < angle of reflection
C. Angle of incidence = angle of reflection
D. Rays do not reflect
✅ Answer: C hecu110

10. A convex lens is also called a:

A. Diverging lens
B. Converging lens
C. Plane lens
D. Reflecting lens
✅ Answer: B hecu110

11. A concave lens always forms an image that is:

A. Real and inverted
B. Virtual, erect and diminished
C. Real and enlarged
D. Virtual and inverted
✅ Answer: B hecu110

12. A convex lens is thicker at the:

A. Edges
B. Centre
C. Pole
D. Focus
✅ Answer: B hecu110

13. A concave lens is thicker at the:

A. Centre
B. Focus
C. Edges
D. Pole
✅ Answer: C hecu110

14. The bending of light when it passes through a lens is called:

A. Reflection
B. Dispersion
C. Refraction
D. Absorption
✅ Answer: C hecu110

15. Which mirror can form a real image?

A. Convex mirror
B. Plane mirror
C. Concave mirror
D. Concave lens
✅ Answer: C

✅ Assertion–Reason Questions (10)

(CBSE Class 8 Standard | Good Quality)

Directions: Choose the correct option:

A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true but R is not the correct explanation of A
C. A is true but R is false
D. A is false but R is true

1.

Assertion (A): A concave mirror is called a converging mirror.
Reason (R): A concave mirror converges parallel rays of light at its focus.
✅ Answer: A hecu110

2.

Assertion (A): A convex mirror always forms a diminished image.
Reason (R): A convex mirror diverges reflected rays and forms a virtual image.
✅ Answer: A hecu110

3.

Assertion (A): Plane mirrors form images of the same size as the object.
Reason (R): The image formed by a plane mirror is always virtual and erect.
✅ Answer: B hecu110

4.

Assertion (A): Convex mirrors are used as rear-view mirrors in vehicles.
Reason (R): Convex mirrors provide a wider field of view.
✅ Answer: A hecu110

5.

Assertion (A): The angle of incidence is equal to the angle of reflection.
Reason (R): This is the first law of reflection.
✅ Answer: A hecu110

6.

Assertion (A): The incident ray, reflected ray, and normal lie in the same plane.
Reason (R): This is the second law of reflection.
✅ Answer: A hecu110

7.

Assertion (A): A convex lens is also called a converging lens.
Reason (R): A convex lens converges parallel rays of light to a point.
✅ Answer: A hecu110

8.

Assertion (A): A concave lens always forms a real image.
Reason (R): A concave lens diverges light rays and forms a virtual image.
✅ Answer: D hecu110

9.

Assertion (A): A concave mirror can form both real and virtual images.
Reason (R): The nature of image depends on the position of the object.
✅ Answer: A hecu110

10.

Assertion (A): Refraction occurs when light changes its path while passing through a lens.
Reason (R): Lenses bend light because light travels at different speeds in different media.
✅ Answer: A

✅ Very Short Answer Questions (10 Questions)

(2 Marks Each | CBSE Class 8 Standard | Good Quality)

1. What is a concave mirror?

Answer:
A concave mirror is a spherical mirror whose reflecting surface is curved inward. It can form real or virtual images depending on the object position. hecu110

2. What is a convex mirror?

Answer:
A convex mirror is a spherical mirror whose reflecting surface bulges outward. It always forms a virtual, erect, and diminished image. hecu110

3. Why are convex mirrors used as rear-view mirrors in vehicles?

Answer:
Convex mirrors provide a wider field of view and always form an erect diminished image, helping drivers see a larger area behind the vehicle. hecu110

4. State the first law of reflection.

Answer:
The first law of reflection states that the angle of incidence is equal to the angle of reflection. hecu110

5. State the second law of reflection.

Answer:
The incident ray, the reflected ray, and the normal at the point of incidence lie in the same plane. hecu110

6. What is the focus of a concave mirror?

Answer:
The focus is the point on the principal axis where parallel rays of light converge after reflection from a concave mirror. hecu110

7. What is the focal length of a mirror?

Answer:
The focal length is the distance between the pole of the mirror and its focus. hecu110

8. What is a convex lens?

Answer:
A convex lens is a transparent lens thicker at the centre. It converges light rays and is called a converging lens. hecu110

9. What is a concave lens?

Answer:
A concave lens is thinner at the centre and thicker at the edges. It diverges light rays and always forms a virtual, erect, diminished image. hecu110

10. What is refraction of light?

Answer:
Refraction is the bending of light when it passes from one medium to another due to a change in its speed.

✅ Short Answer Questions (10 Questions)

(3 Marks Each | CBSE Class 8 Standard | Good Quality)

1. Differentiate between concave and convex mirrors.

Answer:
A concave mirror has its reflecting surface curved inward and can form real or virtual images. A convex mirror has its reflecting surface bulging outward and always forms a virtual, erect, and diminished image. Concave mirrors converge light rays, while convex mirrors diverge them. hecu110

2. Why does a concave mirror form different types of images?

Answer:
A concave mirror can form real or virtual images depending on the position of the object. If the object is placed beyond the focus, a real and inverted image is formed. If it is placed between the pole and focus, a virtual and enlarged image is formed. hecu110

3. Explain the uses of concave mirrors.

Answer:
Concave mirrors are used as dentist mirrors to see enlarged images of teeth. They are also used in torches and headlights to produce parallel beams of light and in solar cookers to concentrate sunlight. hecu110

4. Why are convex mirrors preferred in vehicles?

Answer:
Convex mirrors provide a wider field of view and always form an erect diminished image. This helps drivers see a larger area behind them, reducing blind spots. hecu110

5. State and explain the laws of reflection.

Answer:
The laws of reflection are:

1. The angle of incidence is equal to the angle of reflection.
2. The incident ray, reflected ray, and normal lie in the same plane.
   These laws describe how light reflects from a surface. hecu110

6. Differentiate between convex and concave lenses.

Answer:
A convex lens is thicker at the centre and converges light rays, forming real or virtual images. A concave lens is thinner at the centre and diverges light rays, always forming a virtual, erect, and diminished image. hecu110

7. What kind of image is formed by a convex mirror?

Answer:
A convex mirror always forms a virtual, erect, and diminished image behind the mirror, irrespective of the object position. hecu110

8. Explain the term focal length in lenses.

Answer:
The focal length of a lens is the distance between the optical centre of the lens and its focus. It indicates how strongly the lens converges or diverges light rays. hecu110

9. Describe the image formed by a concave lens.

Answer:
A concave lens always forms a virtual, erect, and diminished image on the same side as the object. It is used in spectacles to correct short-sightedness. hecu110

10. What is refraction? Give one daily life example.

Answer:
Refraction is the bending of light when it passes from one medium to another. Example: A pencil partly dipped in water appears bent due to refraction.

✅ Case-Based Questions (4 Cases)

(4 Marks Each | Sub-questions: 1 + 1 + 2 Marks)
CBSE Competency-Based Standard

Case 1: Concave Mirror in Daily Life

A dentist uses a concave mirror to examine a patient’s teeth. When the mirror is held close to the tooth, the image appears bigger and upright.

Questions:

Q1. (1 Mark) Which type of mirror is used by dentists?
Answer: Concave mirror hecu110

Q2. (1 Mark) What type of image is formed when the object is close to a concave mirror?
Answer: Virtual and erect image hecu110

Q3. (2 Marks) Why is a concave mirror useful for dentists?
Answer:
A concave mirror forms an enlarged upright image when the tooth is placed between the pole and focus, helping the dentist see details clearly. hecu110

Case 2: Convex Mirror as Rear-View Mirror

Vehicles use convex mirrors as side-view mirrors. These mirrors always form erect and diminished images, allowing drivers to see more area behind them.

Questions:

Q1. (1 Mark) Which mirror provides a wider field of view?
Answer: Convex mirror hecu110

Q2. (1 Mark) What is the nature of the image formed by a convex mirror?
Answer: Virtual, erect, and diminished hecu110

Q3. (2 Marks) Why are convex mirrors preferred in vehicles?
Answer:
Convex mirrors provide a wider field of view and reduce blind spots, helping drivers see traffic behind them clearly. hecu110

Case 3: Laws of Reflection

When light falls on a smooth surface like a mirror, it reflects. The reflection follows two laws: angle of incidence equals angle of reflection, and the incident ray, reflected ray, and normal lie in the same plane.

Questions:

Q1. (1 Mark) What is the angle between the incident ray and normal called?
Answer: Angle of incidence hecu110

Q2. (1 Mark) According to the first law, angle of incidence is equal to which angle?
Answer: Angle of reflection hecu110

Q3. (2 Marks) State the second law of reflection.
Answer:
The incident ray, the reflected ray, and the normal at the point of incidence all lie in the same plane. hecu110

Case 4: Convex and Concave Lenses

A convex lens converges light rays and is used in magnifying glasses. A concave lens diverges light rays and is used in spectacles to correct short-sightedness.

Questions:

Q1. (1 Mark) Which lens is called a converging lens?
Answer: Convex lens hecu110

Q2. (1 Mark) Which lens always forms a diminished and erect image?
Answer: Concave lens hecu110

Q3. (2 Marks) Mention one use each of convex and concave lenses.
Answer:
Convex lens is used in magnifying glasses.
Concave lens is used in spectacles for correcting short-sightedness.

✅ Long Answer Questions (5 Questions)

(5 Marks Each | CBSE Class 8 Standard | High Quality Answers)

1. Explain the difference between concave and convex mirrors with their uses.

Answer:
Spherical mirrors are of two types: concave and convex.

Concave Mirror

• Reflecting surface curves inward.
• It converges light rays, so it is called a converging mirror.
• It can form real or virtual images depending on object position.

Uses:

• Dentist mirrors for enlarged images
• Torches and headlights
• Solar cookers

Convex Mirror

• Reflecting surface bulges outward.
• It diverges light rays, so it is called a diverging mirror.
• It always forms a virtual, erect, and diminished image.

Uses:

• Rear-view mirrors in vehicles for wider field of view

Thus, concave mirrors magnify objects while convex mirrors provide a wider view. hecu110

2. State the laws of reflection and explain them with an example.

Answer:
Reflection of light follows two laws:

1. First Law: The angle of incidence is equal to the angle of reflection.
   (∠i = ∠r)
2. Second Law: The incident ray, reflected ray, and the normal at the point of incidence lie in the same plane.

Example:
When light falls on a plane mirror, it reflects in such a way that these laws are always satisfied. This is why we can see our clear image in a mirror. hecu110

3. Describe the images formed by a concave mirror at different object positions.

Answer:
A concave mirror can form different images:

• Object beyond focus: Image is real, inverted, and smaller.
• Object at focus: Image is formed at infinity.
• Object between focus and pole: Image is virtual, erect, and enlarged.

Because of these properties, concave mirrors are used in daily life for magnification and focusing light. hecu110

4. Differentiate between convex and concave lenses with their applications.

Answer:

Convex Lens

• Thicker at the centre, thinner at edges
• Converges light rays
• Forms real or virtual images

Uses:

• Magnifying glass
• Camera lenses
• Spectacles for long-sightedness

Concave Lens

• Thinner at the centre, thicker at edges
• Diverges light rays
• Always forms a virtual, erect, diminished image

Uses:

• Spectacles for short-sightedness
• Door viewers

Thus, convex lenses converge light while concave lenses diverge light. hecu110

5. What is refraction of light? Explain its importance with an example.

Answer:
Refraction is the bending of light when it passes from one medium to another due to a change in speed.

Importance:

• Refraction helps lenses form images.
• It is used in spectacles to correct vision defects.
• It is used in microscopes and telescopes.

Example:
A pencil dipped in water appears bent because light rays change direction while moving from water to air.

Thus, refraction is an important optical phenomenon.