# Full fledge assessment videos for light-reflection-and-refraction

### Refraction and Spherical Lenses - Part 1

Define convex and concave lenses, optical centre, principle axis, centre o...

### Lens Formula, Magnification and Power of a Lens

Define New Cartesian Sign convention, object/image distance, lens formula,...

### Image Formation by Convex Lens

Refraction through Spherical lens

### Sign Conventions for Spherical Mirrors and Mirror Formu...

Define New Cartesian Sign convention, object/image distance, mirror formula...

### Laws of Refraction of Light (Snell's Law)

Explain refraction of light and define rarer/denser medium, refracted ray,...

### Refraction of Light through a Glass Slab and a Prism

Explain the rules for the ray diagram for spherical lenses. Draw ray diagr...

### Refraction and Spherical Lenses - Part 2

Define convex and concave lenses, optical centre, principle axis, centre o...

### Concave Mirrors - Image Formation

Reflection by Spherical mirors

### Image Formation by Concave Lens

Refraction through Spherical lens

### Magnification by Spherical Mirrors

Define New Cartesian Sign convention, object/image distance, mirror formula...

### Image Formation by Plane Mirror - Ray Diagrams

Explain refraction of light and define rarer/denser medium, refracted ray, ...

### Refraction of Light - Exam Decoded - 2

Explain the rules for the ray diagram for spherical lenses. Draw ray diagr...

### Refraction of Light - Exam Decoded - 5

Define convex and concave lenses, optical centre, principle axis, centre o...

### Refraction of Light - Exam Decoded - 4

Define New Cartesian Sign convention, object/image distance, lens formula,...

### Convex Mirrors - Image Formation

Reflection by Spherical mirors

### Refraction of Light - Exam Decoded - 3

Refraction through Spherical lens

### Reflection of Light - Exam Decoded

Define New Cartesian Sign convention, object/image distance, mirror formula...

### Image Formation by Spherical Mirrors - Exam Decoded

Reflection by Spherical mirors

### Refraction of Light - Exam Decoded - 1

Explain refraction of light and define rarer/denser medium, refracted ray,...

Full fledge assessment (Please watch the above videos before attempting this assessment)

Question 1 of 20
Q1. A concave mirror is used in a solar cooker because
• it converges at the focus
• it diverges
• it scatters light rays in all directions
• Both a and b

### Solution :

A concave mirror is used in a solar cooker because it converges at the focus.
Q2. A ____________ is used in a solar cooker.
• Concave mirror
• Convex mirror
• Concave lens
• Convex lens

### Solution :

A concave mirror is used in a solar cooker.
Q3. A concave lens is ________ at the edges.
• steeper
• thinner
• thicker
• tapering

### Solution :

A concave lens is thicker at the edges.
Q4. ________ produces real and inverted images.
• Plane mirror
• Concave mirror
• Convex mirror
• Both a and b

### Solution :

A concave mirror produces real and inverted images.
Q5. The power of a lens in diopters is written as ______.
• • • • All of these

### Solution :

The power of a lens in diopters is written as .
Q6. A convex lens has a focal length of 15 cm. An object must be placed at a distance of ________ in front of the convex lens so as to obtain an image which is real, inverted and of the same size.
• 15 cm
• infinity
• 20 cm
• 30 cm

### Solution :

When the image formed by a convex lens is real, inverted and of the same size as the object, the distance of the object from the lens is 2f.   Since f = 15 cm 2f = 15 × 2 = 30 cm
Q7. Magnification is _______ for a concave lens.
• more than 1
• equal to 1
• more than 2
• less than 1

### Solution :

Magnification is less than 1 for a concave lens.
Q8. __________ is/are the type of spherical mirror.
• Concave
• Plane
• Plano-convex
• Both a and c

### Solution :

Concave is/are the type of spherical mirror.
Q9. If the ‘a’ is object distance, ‘b’ is image distance and ‘c’ is focal length of concave mirror. Then the mirror formula is written as __________.
• • • • ### Solution :

If the ‘a’ is object distance, ‘b’ is image distance and ‘c’ is focal length of concave mirror. Then the mirror formula is written as Q10. In a glass slab, light gets refracted
• once
• twice
• thrice
• four times

### Solution :

In a glass slab, light gets refracted twice.
Q11. A _____________ is also known as a converging mirror.
• Concave mirror
• Convex mirror
• Convex lens
• Both B and C

### Solution :

A concave mirror is also known as a converging mirror.
Q12. When the angle of incidence is greater than the angle of refraction, the light ray
• passes from the rarer to the denser medium
• passes from the denser to the rarer medium
• undergoes reflection
• Both a and c

### Solution :

When the angle of incidence is greater than the angle of refraction, the light ray passes from the rarer to the denser medium.
Q13. When reflected rays pass through the focus, the incident rays pass
• through the centre of curvature
• parallel to the principal axis
• through the principal focus
• obliquely through the pole

### Solution :

When reflected rays pass through the focus, the incident rays pass parallel to the principal axis.
Q14. _________ is not a parameter of the difference in real image and virtual image.
• Screen
• Nature of image
• Type of mirror
• Source of light

### Solution :

Source of light is not a parameter of the difference in real image and virtual image.
Q15. __________ is also known as a converging lens.
• Concave lens
• Convex lens
• Convex mirror
• Both B and C

### Solution :

A convex lens is also known as a converging lens.
Q16. The refractive index of a medium with respect to air is called
• relative refractive index
• grazing angle
• absolute refractive index
• refraction

### Solution :

The refractive index of a medium with respect to air is called absolute refractive index.
Q17. Which of the following is the correct mirror formula?
• R(u + v) = 2uv
• • • All of these

### Solution :

All of three formulae are correct. Solving the above equation R (u + v) = 2uv
Q18. In case of spherical lenses, all distances are measured from the
• optical centre
• direction of light
• pole
• zero point

### Solution :

In case of spherical lenses, all distances are measured from the optical centre.
Q19. If the image formed by a convex mirror is virtual, erect and diminished, then the object is placed
• at the focus
• between the focus and the centre of curvature
• between infinity and the pole
• at infinity

### Solution :

If the image formed by a convex mirror is virtual, erect and diminished, then the object is placed between infinity and the pole.
Q20. If an object is kept at a distance of 30 cm from the plane mirror, the image distance is
• 15 cm
• 20 cm
• 60 cm
• 30 cm

### Solution :

If an object is kept at a distance of 30 cm from the plane mirror, the image distance is 30 cm. Object distance = image distance

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