Chapter 4: Problem 12

A light ray is incident on a plane mirror placed in a horizontal plane, making an angle of $30^{\circ}$ with the vertical, then the angle between the reflected ray and the normal is ________. (1) $35^{\circ}$ (2) $60^{\circ}$ (3) $90^{\circ}$ (4) $30^{\circ}$

Short Answer

Expert verified

Answer: The angle between the reflected ray and the normal is $60^{\circ}$.

Step by step solution

Understand the Laws of Reflection

The laws of reflection state that the angle of incidence is equal to the angle of reflection, and the incident ray, the reflected ray, and the normal to the mirror all lie in the same plane.

Determine the Angle of Incidence

The problem states that the light ray makes an angle of $30^{\circ}$ with the vertical. We need to find the angle between the incident ray and the normal (angle of incidence). The normal is perpendicular to the mirror, so the angle of incidence ($\angle i$) is the complement of the given angle. Since the sum of a vertical angle and its complement is $90^{\circ}$, we can calculate the angle of incidence as follows: $$\angle i = 90^{\circ} - 30^{\circ} = 60^{\circ}$$

Apply the Laws of Reflection

Now that we have the angle of incidence, we can apply the laws of reflection. Because the angle of incidence is equal to the angle of reflection, the angle between the reflected ray and the normal ($\angle r$) is also equal to the angle of incidence. $$\angle r = \angle i = 60^{\circ}$$

Identify the correct option

From the calculation in Step 3, the angle between the reflected ray and the normal is $60^{\circ}$. Therefore, the correct option is (2).

Unlock Step-by-Step Solutions & Ace Your Exams!

Full Textbook Solutions
Get detailed explanations and key concepts
Unlimited Al creation
Al flashcards, explanations, exams and more...
Ads-free access
To over 500 millions flashcards
Money-back guarantee
We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

A light ray is incident on a plane mirror placed in a horizontal plane, making an angle of \(30^{\circ}\) with the vertical, then the angle between the reflected ray and the normal is ________. (1) \(35^{\circ}\) (2) \(60^{\circ}\) (3) \(90^{\circ}\) (4) \(30^{\circ}\)

Short Answer

Step by step solution

Understand the Laws of Reflection

Determine the Angle of Incidence

Apply the Laws of Reflection

Identify the correct option

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Physics Textbooks

Famous Physicists

Magnetism

Scientific Method Physics

Electromagnetism

Wave Optics

Quantum Physics

Study anywhere. Anytime. Across all devices.