Optics & Light Phenomena Quiz

During a school science project, a student places a cardboard cutout of a tree in front of a bright lamp. If the student moves the lamp closer to the cutout, which observation would most likely be true regarding the shadow formed?

1. The shadow becomes shorter and sharper.
2. The shadow becomes longer and more diffuse.
3. The shadow disappears entirely.
4. The shadow's shape changes dramatically.

Answer: (a) The shadow becomes shorter and sharper.

What role does the pinhole play in maintaining the laws of reflection inside a pinhole camera?

1. It amplifies the light intensity for a clearer image.
2. It reflects light to form the image.
3. It prevents reflection from occurring.
4. It allows only straight light paths, creating an inverted image.

Answer: (d) It allows only straight light paths, creating an inverted image.

A flat mirror is used in a funhouse. If a person stands 5 metres from the mirror, how far away will their image appear to be from them?

1. 0 m
2. 5 m
3. 10 m
4. 20 m

Answer: (c) 10 m

Sofia uses a plane mirror to practice her dance moves. Which property of the mirror allows her to see her full reflection?

1. The mirror reflects light in all directions.
2. The mirror creates an inverted image.
3. The mirror changes the color of the objects reflected.
4. The mirror produces an image that is the same size as the object.

Answer: (d) The mirror produces an image that is the same size as the object.

A student wants to create a makeshift periscope using two flat mirrors. If one mirror is placed at the bottom of a box and the other is at the top, what should the angle of each mirror be to allow the student to see outside from the bottom of the box?

1. 30°
2. 45°
3. 60°
4. 90°

Answer: (b) 45°

A plane mirror is installed at a 45° angle on the ground. A light ray shines directly onto it from above. In which direction will the reflected ray travel?

1. Horizontally across the ground.
2. Back upwards at the same angle as it arrived.
3. Towards the source of light.
4. At a 45° angle to the incoming ray.

Answer: (a) Horizontally across the ground.

The diagram below shows a torch shining on a square piece of clear glass and a ball. A shadow is cast on the screen. What could be done to enlarge the shadow?

1. Remove the clear glass
2. Move the ball nearer to the screen
3. Move the ball nearer to the clear glass
4. Move the torch away from the clear glass

Answer: (c) Move the ball nearer to the clear glass

Peter made some observations when three objects X, Y and Z were placed in between the light source and a screen one at a time. The observations were recorded in the table as shown below: Object Observation X Dark shadow was formed. Y Light shadow was formed. Z No shadow was formed. Which of the following explains why the above observations were made? A. Object X is opaque while Object Z is transparent. B. Object Y is placed furthest away from the light source. C. The path of light was blocked by at least one of the objects.

1. A and B only
2. B and C only
3. A and C only
4. A, B and C

Answer: (c) A and C only

The diagram below shows a connection of pipes. 3 mirrors are placed inside the pipes. In order to see an object through the pipes, where should the eye and the object be placed respectively?

1. Position of object - A Position of eye - D
2. Position of object - B Position of eye - C
3. Position of object - C Position of eye - A
4. Position of object - D Position of eye - B

Answer: (b) Position of object - B Position of eye - C

The diagram below shows the positions of the shadow cast by a stick at four different times of a day. Match each shadow to the correct time.

1. 1
2. 2
3. 3
4. 4

Answer: (d) 4