Quiz for Refraction

Q1: When light travels from air to glass, what happens to its speed?

A. Increases B. Decreases C. Remains same D. Becomes zero

Q2: The refractive index of a medium is defined as:

A. c/v B. v/c C. 1 - v/c D. v - c

Q3: Snell’s law is given by:

A. n1n2 = sinθ2/sinθ1 B. n1sinθ1 = n2sinθ2 C. n1 = sinθ2/sinθ1 D. n2 = sinθ1/sinθ2

Q4: Critical angle occurs when light passes from:

A. denser to rarer medium B. rarer to denser medium C. vacuum to air D. air to glass

Q5: If the angle of incidence is equal to the critical angle, the angle of refraction is:

A. 0° B. 45° C. 90° D. 180°

Q6: A real image formed by a lens is always:

A. Erect B. Inverted C. Virtual D. Magnified

Q7: The focal length of a convex lens is:

A. Positive B. Negative C. Zero D. Undefined

Q8: A diverging lens is:

A. Convex B. Concave C. Plano-convex D. None

Q9: Refractive index of water is 1.33. It means:

A. Light travels faster in water than in air B. Light slows down in water C. Light stops in water D. Light reflects fully

Q10: Which of the following is a condition for total internal reflection?

A. Light must travel from rarer to denser medium B. Angle of incidence must be less than critical angle C. Angle of incidence must be greater than critical angle D. Light must be monochromatic

Q11: Lens formula is given by:

A. 1/v - 1/u = 1/f B. 1/v + 1/u = 1/f C. 1/f = uv D. v = uf

Q12: A virtual image formed by a convex lens is when:

A. Object is at 2f B. Object is beyond 2f C. Object is between lens and focus D. Object is at infinity

Q13: The power of a lens in diopters is:

A. 1/f (f in cm) B. f (in cm) C. 1/f (f in m) D. f (in m)

Q14: Real depth and apparent depth are related by:

A. Apparent depth = real depth / refractive index B. Real depth = apparent depth / refractive index C. Apparent depth = real depth * refractive index D. None

Q15: In an optical fiber, light is transmitted due to:

A. Reflection B. Diffraction C. Total internal reflection D. Polarization

Q16: When white light enters a prism, dispersion occurs because:

A. Different colors have different speeds in glass B. White light is absorbed C. Prism reflects light D. Glass is opaque

Q17: Refraction does not occur when:

A. Light travels from air to water B. Light passes from one medium to another C. Light travels perpendicular to boundary D. Light changes speed

Q18: If refractive index of glass is 1.5, the speed of light in glass is:

A. 2 × 10^8 m/s B. 1.5 × 10^8 m/s C. 3 × 10^8 m/s D. 4.5 × 10^8 m/s

Q19: The radius of curvature of a lens is related to focal length by:

A. f = R B. f = R/2 C. f = 2R D. f = R/4

Q20: A concave lens always forms:

A. Real and inverted image B. Virtual and erect image C. Real and erect image D. Inverted and magnified image