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Light – Reflection and Refraction — Class 10 CBSE Science MCQs with Solutions
Free Class 10 CBSE Science Light – Reflection and Refraction MCQs with step-by-step solutions. Practise online on Prepizo — no login needed.
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Sample questions with solutions
Q1 — easy
Focal length (f) and radius of curvature (R) of a spherical mirror are related by formula:
A. f = 2R
B. f = R / 2 ✓ Correct
C. f = R²
D. f = 1/R
Solution: Focal length is half the radius of curvature: f = R/2.
Q2 — easy
Concave mirror forms a virtual, erect, and enlarged image of an object when placed:
A. At focus F
B. Between Pole P and Focus F ✓ Correct
C. At Center of Curvature C
D. Beyond C
Solution: Placing object between P and F produces a virtual enlarged image.
Q3 — easy
Which mirror is used by drivers as a rear-view mirror in vehicles because it provides a wide field of view and erect diminished image?
A. Concave mirror
B. Convex mirror ✓ Correct
C. Plane mirror
D. Parabolic mirror
Solution: Convex mirrors form upright, diminished images with broad field of view.
Q4 — easy
Which mirror is used in solar furnaces and dentist headlamps to concentrate light rays?
A. Convex mirror
B. Concave mirror ✓ Correct
C. Plane mirror
D. Cylindrical mirror
Solution: Concave mirrors converge parallel rays to a focal point.
Q5 — easy
Standard Spherical Mirror Formula relating u, v, and f is:
A. (1/v) − (1/u) = 1/f
B. (1/v) + (1/u) = 1/f ✓ Correct
C. v + u = f
D. f = u × v
Solution: Mirror formula: (1/v) + (1/u) = 1/f.
Q6 — easy
Magnification (m) produced by a spherical mirror in terms of object distance u and image distance v is:
A. m = −v / u ✓ Correct
B. m = +v / u
C. m = u / v
D. m = −u / v
Solution: Mirror magnification m = −v/u = hᵢ/hₒ.
Q7 — easy
When light travels from an optically rarer medium to a denser medium (e.g. air to glass), it bends:
A. Away from normal
B. Toward normal ✓ Correct
C. Undeviated
D. Back into same medium
Solution: Light slows down in denser media, bending toward the normal.
Q8 — easy
Absolute Refractive Index (n) of a medium is defined as ratio of speed of light in vacuum (c) to:
A. Speed of light in medium (v) ✓ Correct
B. Speed of sound in medium
C. Angle of incidence
D. Wavelength in medium
Solution: n = c / v.
Q9 — easy
Snell's Law of Refraction states that ratio of sine of angle of incidence to sine of angle of refraction is constant, written as:
A. sin i × sin r = n
B. sin i / sin r = constant (n₂₁) ✓ Correct
C. sin r / sin i = constant
D. i / r = n
Solution: sin i / sin r = n₂₁.
Q10 — easy
Standard Thin Lens Formula relating u, v, and f is:
A. (1/v) + (1/u) = 1/f
B. (1/v) − (1/u) = 1/f ✓ Correct
C. (1/f) + (1/v) = 1/u
D. f = v − u
Solution: Lens formula: (1/v) − (1/u) = 1/f.
Q11 — easy
Power of a lens (P) is reciprocal of its focal length f in metres. Formula and SI unit are:
A. P = 1/f (in m), Dioptre (D) ✓ Correct
B. P = f (in cm), Dioptre
C. P = 100/f (in m), Watt
D. P = f², Meter
Solution: P = 1/f(m), measured in Dioptres (D).
Q12 — easy
A convex lens has focal length f = +20 cm (+0.2 m). Its optical power P is:
A. +2 D
B. +5 D ✓ Correct
C. −5 D
D. +0.2 D
Solution: P = 1 / 0.2 m = +5 D.
Q13 — easy
A concave lens always forms an image that is:
A. Real, inverted, enlarged
B. Virtual, erect, diminished ✓ Correct
C. Real, erect, diminished
D. Virtual, inverted, enlarged
Solution: Diverging concave lenses form virtual, upright, diminished images.
Q14 — easy
An object placed at 2F₁ in front of a convex lens forms an image at:
A. Focus F₂
B. 2F₂ (same size, real, inverted) ✓ Correct
C. Infinity
D. Between F₂ and 2F₂
Solution: Object at 2F₁ yields equal-sized real inverted image at 2F₂.
Q15 — easy
A ray of light passing through optical center (O) of a thin lens emerges:
A. Bent toward principal focus
B. Without any deviation ✓ Correct
C. Reflected back
D. Parallel to axis
Solution: Light passing through optical center travels undeviated.