First, this article gives you 20 original MCQs on reflection of light in physical science. Moreover, the questions suit students who prepare for RRB NTPC, SSC exams, and UPSC at a moderate level. Also, you will learn the laws of reflection, plane mirror images, concave and convex mirrors, and the mirror formula. Next, you can attempt each question first and then check the correct answer. After that, you should read the Extra Information to understand the concept clearly. Therefore, you will build both speed and accuracy with regular practice. Finally, you can repeat the set before your exam to strengthen your light reflection concepts.
Laws of Reflection and Basic Terms MCQs
Q1
What does the second law of reflection state about the two angles?
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Answer: B) The angle of incidence equals the angle of reflection
First, the incident ray, the reflected ray, and the normal lie in one plane. Moreover, this statement forms the first law of reflection. As a result, both laws together predict the path of every reflected ray. However, the laws work for smooth and rough surfaces alike. Finally, students often use these laws to solve ray diagram problems.
Q2
A ray strikes a plane mirror at 30° to the mirror surface. What angle of reflection does it give?
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Answer: D) 60°
Also, the angle of incidence measures the angle between the incident ray and the normal. Besides, many students wrongly measure it from the mirror surface. Therefore, you must subtract 30° from 90° in this case. In contrast, the angle of reflection also uses the normal as its reference. Overall, both angles stay equal at 60°.
Q3
Which line stands at 90° to the mirror surface at the point of incidence?
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Answer: A) Normal
In fact, the normal helps us measure every angle in reflection problems. Additionally, a ray along the normal bounces straight back along its own path. For this reason, its angle of incidence and angle of reflection both equal 0°. For example, a torch beam that hits a mirror head-on returns to the torch. Thus, the normal acts as a reference line for every ray diagram.
Q4
Which type of reflection lets people see a non-shiny wall from every direction?
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Answer: C) Diffuse reflection
First, rough surfaces such as paper, walls, and cloth scatter light in many directions. Moreover, each tiny part of the surface still follows the laws of reflection. Because of this, reflected rays spread out and reach many eyes. Still, no clear image forms on such surfaces. In short, diffuse reflection lets us see objects that do not shine.
Plane Mirror Image MCQs
Q5
Which pair of words correctly describes the image in a plane mirror?
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Answer: C) Virtual and erect
Also, the image forms because reflected rays only appear to meet behind the mirror. Besides, you cannot catch this virtual image on a screen. Consequently, the image looks erect and has the same size as the object. In contrast, a real image can appear on a screen. Finally, the image also shows left-right reversal, which people call lateral inversion.
Q6
A person stands 2 m in front of a plane mirror. How far is the person from their image?
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Answer: A) 4 m
First, the plane mirror forms an image at the same distance behind it. Furthermore, the object and the image stay on opposite sides of the mirror. Hence, the person stands 2 m away and the image appears 2 m behind. However, the total gap between them becomes 4 m. Overall, you must add both distances in such questions.
Q7
How many images do two plane mirrors form when they meet at 90°?
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Answer: D) 3
In fact, you can find the number of images with the formula 360 divided by the angle, minus 1. In addition, this formula works when 360 divided by the angle gives a whole number. As a result, a 90° angle gives 3 images. For instance, a 60° angle gives 5 images. Thus, a smaller angle produces more images.
Q8
A plane mirror turns by 15° while the incident ray stays still. By how much does the reflected ray turn?
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Answer: B) 30°
Next, the law of reflection explains this doubling effect. Moreover, the normal turns by 15° along with the mirror. Therefore, the reflected ray turns by twice that angle, which is 30°. Still, the incident ray stays fixed during the turn. In short, the reflected ray always turns by double the mirror’s rotation.
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Spherical Mirror Terms and Uses MCQs
Q9
Which point sits at the centre of a spherical mirror’s reflecting surface?
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Answer: A) Pole
Also, the pole sits at the geometric centre of the mirror surface. Besides, the line through the pole and the centre of curvature forms the principal axis. As a result, you measure all distances from the pole. Meanwhile, the aperture means the width of the reflecting surface. Overall, these terms form the base of every mirror problem.
Q10
A concave mirror has a radius of curvature of 30 cm. How long is its focal length?
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Answer: C) 15 cm
First, the focal length equals half the radius of curvature. Moreover, the formula f = R/2 works for both concave and convex mirrors. For this reason, a 30 cm radius gives a 15 cm focal length. However, the sign convention gives a concave mirror a negative focal length. Thus, you must check the sign in numerical questions.
Q11
Which mirror do manufacturers fit as the outside rear-view mirror in vehicles?
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Answer: B) Convex mirror
In fact, a convex mirror always forms a virtual, erect, and smaller image. Additionally, it gives drivers a wide field of view. Because of this, drivers can see more traffic behind them. For example, a side mirror shows several lanes at once. Finally, the smaller image makes objects look farther than they really are.
Q12
Which mirror do dentists use to see enlarged images of teeth?
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Answer: D) Concave mirror
First, a concave mirror forms an enlarged, erect image when the object stands between the pole and the focus. In addition, the dentist places the mirror close to the tooth. Therefore, the dentist sees a clear and magnified view. In contrast, a convex mirror would shrink the view. Besides, shaving mirrors use the same enlarging property.
Image Formation by Concave and Convex Mirrors MCQs
Q13
An object stands at the centre of curvature of a concave mirror. What kind of image forms?
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Answer: D) Real, inverted, and same size
In fact, the object and its image sit at the same distance from the mirror here. Furthermore, both distances equal the radius of curvature. As a result, the image has a magnification of −1. Still, the minus sign only shows that the image is inverted. Thus, this position gives a real, inverted, same-size image.
Q14
An object stands very far from a concave mirror. Where does the image form?
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Answer: B) At the focus
First, parallel rays from a far object meet at the focus after reflection. Next, this meeting point forms a tiny, real, inverted image. Therefore, the image appears highly diminished. For example, a concave mirror can focus sunlight onto a small bright spot. In short, solar cookers and furnaces use this effect.
Q15
An object stands between the focus and the centre of curvature of a concave mirror. Where does the image form?
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Answer: A) Beyond the centre of curvature
Also, the image grows larger as the object moves closer to the focus. Moreover, the image shifts farther away from the mirror. Because of this, the image forms beyond the centre of curvature. However, it stays real and inverted. Finally, you can see this pattern clearly in ray diagrams.
Q16
Where does a convex mirror form the image of a very distant object?
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Answer: C) At the focus behind the mirror
Next, parallel rays spread out after they hit a convex mirror. Besides, they appear to come from the focus behind the mirror. Therefore, the image forms there as a tiny virtual point. In contrast, a concave mirror brings the rays together in front. Overall, a convex mirror never forms a real image of a real object.
Mirror Formula and Everyday Applications MCQs
Q17
A concave mirror has a focal length of 10 cm. An object stands 15 cm from the mirror. How far from the mirror does the image form?
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Answer: B) 30 cm
First, you write the mirror formula as 1/v + 1/u = 1/f. Then, you apply the sign convention, so u = −15 cm and f = −10 cm. As a result, 1/v equals −1/30. However, many students forget the negative signs here. Thus, v equals −30 cm, which means the image forms 30 cm in front of the mirror.
Q18
Which formula gives the magnification of a spherical mirror?
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Answer: A) m = −v/u
In fact, magnification compares image height with object height. Also, the formula m = −v/u links this ratio to the distances. Because of this, a negative value shows an inverted image. In contrast, a positive value shows an erect image. Finally, a plane mirror always gives m = +1.
Q19
A person wants to see their full image in a plane mirror. What minimum mirror height do they need?
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Answer: D) Half of their height
First, light travels from the person’s head and feet to the mirror. Moreover, the reflected rays reach the eye at equal angles. As a result, the mirror needs only half the person’s height. However, the mirror must hang at the right level. For example, the top edge should sit halfway between the eyes and the top of the head.
Q20
Which device lets submarine crews see above the water with plane mirrors?
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Answer: C) Periscope
In fact, a periscope uses two parallel plane mirrors that sit at 45° to the tube. Next, the top mirror reflects incoming light down the tube. Then, the lower mirror sends the light into the viewer’s eye. As a result, submarine crews see above the water while they stay below. Finally, soldiers in trenches also use this simple device.
Final Thoughts on Reflection of Light MCQs
Overall, these MCQs cover the key facts about reflection of light. Moreover, they include the laws of reflection, plane mirror images, and spherical mirrors. Also, the set shows how the mirror formula helps you solve numerical questions. Therefore, you should practise the MCQs again and review every Extra Information note. Next, you can take timed tests to improve your speed for RRB NTPC, SSC exams, and UPSC. In addition, you can draw ray diagrams by hand to remember image positions. Finally, keep practising with patience, because steady effort builds confidence and good marks.