Introduction to Reflection

A light ray strikes a smooth mirror so that the angle between the incident ray and the normal is 35°. According to the laws of reflection, what will be the angle between the reflected ray and the normal?

• 35°

• 55°

• 70°

• Cannot be determined without the refractive index

Which statement best distinguishes specular reflection from diffuse reflection when the same light beam hits different surfaces?

• Specular reflection occurs on rough surfaces and sends rays in random directions; diffuse reflection occurs on smooth surfaces and keeps rays parallel.

• Specular reflection occurs on smooth surfaces and reflects rays in a single predictable direction; diffuse reflection occurs on rough surfaces and scatters rays.

• Specular reflection and diffuse reflection both require curved mirrors to occur.

• Specular reflection changes the color of light while diffuse reflection does not.

A ray of light strikes a plane mirror with an angle of incidence of 35° measured from the normal. According to the laws of reflection, what is the angle of reflection?

• 0°

• 35°

• 55°

• 90°

A ray from point A strikes a plane mirror at point C. The normal at C is perpendicular to the mirror. The incident ray makes an angle θ with the normal, and the reflected ray leaves making the same angle θ on the other side of the normal, reaching point E. Which principle justifies the equal angles and predicts the path to E?

• Refraction law (Snell’s law)

• Law of conservation of energy

• Law of reflection

• Superposition principle

A plane mirror inside a submarine periscope reflects the image of a ship on the sea surface. Which statement best explains how the periscope allows the observer below the waterline to see above the surface?

• Light from objects above the surface travels straight through water to the observer without reflection.

• Light from objects above the surface enters the periscope and is reflected by plane mirrors so the ray is redirected down to the observer.

• The periscope magnifies objects using lenses without any mirrors, so reflection is not involved.

• The periscope creates virtual images using curved mirrors that invert the scene.

A ray of light strikes a flat mirror with an angle of incidence of 35° measured from the normal. What is the angle that the reflected ray makes with the mirror surface? Assume ideal reflection. (Hint: angle with surface = 90° − angle with normal.)

• 35°

• 55°

• 70°

• 90°

A plane mirror produces which type of image, and what is a defining feature of this image?

• Real and inverted; can be projected on a screen

• Virtual and upright; appears behind the mirror

• Real and upright; larger than the object

• Virtual and inverted; appears in front of the mirror

A bank wants customers at an ATM to quickly check if someone is behind them. Which mirror type best serves this purpose, and why?

• Plane mirror, because it forms life-size images without distortion

• Concave mirror, because it focuses light to a point for bright illumination

• Convex mirror, because it provides a wider field of view with small, erect images

• Parabolic mirror, because it eliminates spherical aberration

Which scenario best explains why concave mirrors are used in car headlights?

• They disperse light in all directions to reduce glare.

• They focus light from the bulb into a parallel beam for a longer, brighter reach.

• They invert the image of the bulb to reduce intensity.

• They absorb stray light to prevent reflections.

A driver wants a mirror that shows a wider field of view to monitor traffic behind the car. Which mirror type best meets this need and is commonly used as the rearview mirror?

• Plane mirror

• Concave mirror

• Convex mirror

• Parabolic mirror