Kerala SSLC · Physics · Class 10
Light – Reflection: Important Questions with Answers
These are 10 important multiple-choice questions from the Kerala SSLC Physics chapter “Light – Reflection” (Kerala SCERT syllabus). Each one shows the correct answer and a short explanation of why it is right. Try answering before you read the answer. ExamSummary has 10 practice questions on this chapter in total.
Q1.According to the first law of reflection, if the angle of reflection is 45 degrees, what is the angle of incidence?
- A)45 degrees
- B)90 degrees
- C)0 degrees
- D)180 degrees
Answer: A) 45 degrees
The first law of reflection states that the angle of incidence is always equal to the angle of reflection. Therefore, if the angle of reflection is 45 degrees, the angle of incidence must also be 45 degrees.
Q2.For a spherical mirror with a radius of curvature of 20 cm, what is its focal length?
- A)10 cm
- B)20 cm
- C)40 cm
- D)5 cm
Answer: A) 10 cm
The focal length of a spherical mirror is exactly half of its radius of curvature. Thus, dividing 20 cm by 2 gives a focal length of 10 cm.
Q3.Where should an object be placed in front of a concave mirror to form a real, inverted, and magnified image?
- A)At the focus
- B)Between the pole and the focus
- C)Between the focus and the center of curvature
- D)Beyond the center of curvature
Answer: C) Between the focus and the center of curvature
When an object is placed between the focus and the center of curvature, the reflected rays converge to form a real, inverted, and magnified image beyond the center of curvature.
Q4.Why are convex mirrors preferred as rear-view mirrors in vehicles?
- A)They produce magnified images for better visibility
- B)They produce real images that can be projected on a screen
- C)They produce erect and diminished images giving a wider field of view
- D)They reflect all the light falling on them without absorption
Answer: C) They produce erect and diminished images giving a wider field of view
Convex mirrors always form virtual, erect, and diminished images regardless of the object's position. This property allows the driver to see a much wider area of traffic behind the vehicle.
Q5.If an object is placed at infinity in front of a concave mirror, where will the image be formed?
- A)At the center of curvature
- B)At the focus
- C)At infinity
- D)Behind the mirror
Answer: B) At the focus
Rays coming from an object at infinity are parallel to the principal axis. Upon reflection from a concave mirror, these rays converge and meet at the principal focus.
Q6.What does a negative magnification value indicate about the image formed by a mirror?
- A)The image is virtual and erect
- B)The image is real and inverted
- C)The image is smaller than the object
- D)The image is larger than the object
Answer: B) The image is real and inverted
In the sign convention for mirrors, a negative magnification indicates that the image is real and inverted relative to the object. A positive magnification would indicate a virtual and erect image.
Q7.The point on the principal axis where all rays parallel to it appear to diverge from after reflection from a convex mirror is called the ________.
- A)Pole
- B)Center of Curvature
- C)Principal Focus
- D)Vertex
Answer: C) Principal Focus
For a convex mirror, the principal focus is a virtual point located behind the mirror where reflected rays appear to diverge from when incident rays are parallel to the principal axis.
Q8.Which type of mirror is typically used as a shaving mirror to see a magnified image of the face?
- A)Plane mirror
- B)Convex mirror
- C)Concave mirror
- D)Cylindrical mirror
Answer: C) Concave mirror
A concave mirror is used as a shaving mirror because when the face is placed between the pole and the focus, it produces a magnified, erect, and virtual image suitable for detailed viewing.
Q9.A ray of light incident on a concave mirror passes through the focus before striking the mirror. After reflection, this ray will travel ________.
- A)Parallel to the principal axis
- B)Through the center of curvature
- C)Back along the same path
- D)Perpendicular to the surface
Answer: A) Parallel to the principal axis
According to the specific rules of reflection for spherical mirrors, any ray passing through the principal focus before striking the mirror will reflect parallel to the principal axis.
Q10.According to the New Cartesian Sign Convention, how is the focal length of a concave mirror represented?
- A)Positive
- B)Negative
- C)Zero
- D)Infinity
Answer: B) Negative
In the New Cartesian Sign Convention, distances measured opposite to the direction of incident light are taken as negative. Since the focus of a concave mirror lies in front of the mirror, its focal length is negative.