A ray of light is incident on a plane mirror at an angle of 40 with respect to surface normal. When it gets reflected from the mirror, it undergoes a deviation of

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Q: 13 (CDS-II/2017)
A ray of light is incident on a plane mirror at an angle of 40° with respect to surface normal. When it gets reflected from the mirror, it undergoes a deviation of

question_subject: 

Science

question_exam: 

CDS-II

stats: 

0,6,20,12,6,4,4

keywords: 

{'plane mirror': [0, 0, 0, 7], 'mirror': [0, 0, 0, 1], 'angle': [0, 0, 1, 0], 'ray': [2, 0, 5, 15], 'light': [16, 4, 34, 62], 'deviation': [0, 0, 0, 1]}

When a ray of light is incident on a plane mirror, it follows the law of reflection, which states that the angle of incidence is equal to the angle of reflection. In this case, the ray of light is incident at an angle of 40° with respect to the surface normal. The angle of incidence is the angle between the incident ray and the surface normal.

Since the angle of incidence is 40°, the angle of reflection will also be 40°. Therefore, the deviation of the ray of light after reflection from the mirror is equal to the angle of reflection, which is 40°.

Option 1 (40°) is the correct answer because it matches the angle of reflection.

Option 2 (100°) is incorrect because it does not match the angle of reflection.

Option 3 (90°) is incorrect because it does not take into account the law of reflection.

Option 4 (80°) is incorrect because it does not match the angle of reflection.

Alert - correct answer should be 1 (40°)