Mirror Coverage and Image – Rankers Physics

Reflection by Spherical Mirrors: Practice Problem & Solution

Assertion (A): If one half of a mirror is covered by an opaque material, then only half image of the object is formed. Reason (R): By covering one half of the mirror, focal length of mirror will be halved.  
Both (A) & (R) are true and the (R) is the correct explanation of the (A)
Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(A) is true but (R) is false
Both (A) and (R) are false

Solution Explained:

To solve this problem, we apply the core principles of Reflection by Spherical Mirrors. Understanding the underlying formula is key to arriving at the correct answer below:

Covering half a mirror reduces the intensity of the image but a complete image is still formed. The focal length of a mirror depends only on its radius of curvature, not on the aperture or how much of its surface is exposed.

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Similar Practice Questions

Explore conceptually related problems to test your knowledge.

1. Assertion (A): An object placed at a distance less than \(25 \text{ cm}\), in front of a normal eye. The image of this object on retina is blurred. Reason (R): Image is formed before retina.  
2. Assertion (A): The sun appears oval shape at sunrise. Reason (R): At the time of sunrise sun appears a little before the actual sunrise.  
3. Assertion (A): The refractive index of diamond is \(\sqrt{6}\), and that of liquid is \(\sqrt{3}\), . If the light travels from diamond to the liquid, it will totally reflected when the angle of incidence is \(30^\circ\). Reason (R): For total internal reflection, angle of incidence should be less than critical angle \(\theta_c = sin^{-1}(\frac{1}{\mu})\).
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