Physics

Ray Optics and Mirrors

115 Questions

Ray optics covers the principles of light reflection and refraction through mirrors and lenses. The questions focus on focal length, magnification, and image formation. This physics topic is highly relevant for exams requiring science aptitude.

Concave mirror imagesConvex lens formulasFocal length calculationsMagnification ratiosImage distance

Ray Optics and Mirrors Questions

Multiple choice

In case of hypermetropia

  1. the image of a distant object is formed in front of the retina

  2. the image of a near object is formed behind the retina

  3. a concave lens should be used for correction

  4. a convex lens cannot be used for correction
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hypermetropia, or farsightedness, occurs when the eyeball is too short or the lens has insufficient converging power. This causes the image of nearby objects to be focused behind the retina rather than on it.

Multiple choice physics reflection of light at curved surfaces the mirror formula derivation of formula for curved mirrors mirror formula and magnification

What is the formula for spherical mirrors for object distance p and image distance q ?

  1. $\dfrac{1}{p}+q=\dfrac{1}{f}$
  2. $\dfrac{1}{p}+\dfrac{1}{q}=\dfrac{1}{f}$
  3. $\dfrac{1}{p}+\dfrac{1}{q}=f$
  4. $p+\dfrac{1}{q}=\dfrac{1}{f}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Mirror formula is given as: 
$ \dfrac{2}{R} = \dfrac{1}{v} + \dfrac{1}{u} $

where, $ R $ is the radius of curvature of the spherical mirror
$u $ is the object distance from the pole
$ v $ is the image distance from the pole

We know,
$ f = \dfrac{R}{2} $

$ \Rightarrow \dfrac{1}{f} = \dfrac{1}{v} + \dfrac{1}{u} $

$ \therefore $ For object distance $ p $ and image distance $ q $, mirror formula becomes
$ \dfrac{1}{f} = \dfrac{1}{p} + \dfrac{1}{q} $

Hence, the correct answer is OPTION B.
Multiple choice physics reflection of light at curved surfaces the mirror formula derivation of formula for curved mirrors mirror formula and magnification

A point source of light is kept in front of a convex mirror of radius of curvature $40 cm$. The image is formed at $10 cm$ behind the mirror. Calculate the object distance

  1. 30

  2. 20

  3. 50

  4. 40
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Given: For a convex mirror, $R = -40 cm$.
$v = -10 cm$ (image is virtual).
From mirror formula, we have

$\displaystyle \frac {2}{R}=\frac {1}{u}+\frac {1}{v}$

$\displaystyle \frac {1}{u}=\frac {2}{R}-\frac {1}
{v}=\frac {2v-R}{vR}$

$\displaystyle u=\frac {vR}{2v-R}=\frac {(-10cm) \times (-40cm)}{2 \times (-10cm) - (-40cm)}$

$=+20cm$
Thus, object is placed $20 cm$ in front of the mirror.

Multiple choice evs magic with mirrors lateral inversion right or left reflection at plane surface

Why is AMBULANCE written laterally inverted on an Ambulance van?

  1. It gathers more attention since it is laterally inverted.

  2. Vehicle in front sees a laterally inverted image and perceives it correctly, hence giving side to the ambulance van.

  3. Vehicle in front sees a virtually erect image and perceives it correctly, hence giving side to the ambulance van.

  4. None of the above.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ambulance is usually in a hurry. In order to convey the vehicle in front that it is an ambulance, it is written laterally inverted. When the driver of the vehicle in front reads through the rear-view mirror, the Image of this inscription, through lateral inversion, form a right oriented image.

Multiple choice conditions for a light ray to pass undeviated refraction of light at plane surfaces physics

A mark is made on the surface of a glass sphere of diameter 10 cm and refractive index 1.5 . it its viewed through the glass from a potion directly opposite . the distance of the image of the mark from the centre of the sphere will be 

  1. 20 cm

  2. 17.5 cm

  3. 15 cm

  4. 22.5 cm
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Using the refraction formula at a spherical surface: (mu2 / v) - (mu1 / u) = (mu2 - mu1) / R. Here, the object is on the surface, so u = -10 cm (diameter). mu1 = 1.5, mu2 = 1, R = -5 cm. (1 / v) - (1.5 / -10) = (1 - 1.5) / -5 => 1/v + 0.15 = 0.1 => 1/v = -0.05 => v = -20 cm. The image is 20 cm from the pole, which is 20 cm from the center.