Light and Sound Quiz

Look at the table showing different actions and the materials involved. Which property best explains why sound is heard in some cases and not in others? Action Sound Heard? Blowing into a plastic tube Yes Dropping a feather No Striking a metal bar Yes Rubbing two pieces of wool No

1. Vibrations are needed to produce sound
2. Sound can only be made by soft materials
3. Only hollow objects produce sound
4. Sound needs wind to travel

Answer: (a) Vibrations are needed to produce sound

Which of the following statements are TRUE about how sound travels? 1. Sound can travel through solids, liquids, and gases. 2. Sound can travel even through vacuum. 3. Sound travels faster in air than in steel. 4. Sound needs a medium to travel.

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

Answer: (d) 1 and 4

A company wants to design a classroom bell system that can be heard even in nearby rooms. Which design is most effective?

1. Use a tiny bell placed on the wall
2. Use a vibrating phone without sound
3. Use a large metal bell and place it on a wooden board
4. Use a large metal bell placed on a concrete wall

Answer: (d) Use a large metal bell placed on a concrete wall

Lina is building a model city. She places the following things on her model: 1. A lamp post with a bulb 2. A glow-in-the-dark sticker 3. A small sun model (a glowing ball) 4. A mirror reflecting sunlight Which TWO objects are truly sources of light?

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

Answer: (a) 1 and 3

Which of the following actions does not involve bending or changing direction of light?

1. A coin disappearing in a glass of water
2. A straw appearing broken in lemonade
3. Light bouncing off a metal spoon
4. A rainbow appearing in the sky

Answer: (c) Light bouncing off a metal spoon

Imagine you are designing a new outdoor street lamp. The lamp should provide light to people but should not disturb nearby homes with bright lights at night. Which material would you use for the lamp cover to achieve this goal?

1. Transparent glass
2. Translucent plastic
3. Opaque metal
4. Clear acrylic

Answer: (b) Translucent plastic

If the object is moved from 10 cm to 40 cm from the light source, what will happen to the shadow?

1. The shadow will become smaller as the object moves away.
2. The shadow will stay the same size.
3. The shadow will become larger as the object moves away
4. The shadow will change shape, but not size.

Answer: (a) The shadow will become smaller as the object moves away.

A laser pointer is aimed through 3 straight tubes joined together. If tube 2 is bent slightly, what will happen to the light at the end?

1. It will still come out straight
2. It will bend with the tube
3. It won’t come out — light only travels straight
4. It will bounce around and get brighter

Answer: (c) It won’t come out — light only travels straight

You’re setting up a light-based puppet show. You want clear shadows of your puppets on the screen. Which material should you use for the puppets and why?

1. Plastic sheet – it glows in the dark
2. Glass – clear and transparent
3. Cardboard – blocks light to form shadows
4. Foil paper – shiny and reflects light

Answer: (c) Cardboard – blocks light to form shadows

What should be the correct sequence for how a drum produces sound? A. The drumhead vibrates after being struck. B. The air particles around the drumhead start vibrating. C. We hear the sound as the vibrations reach our ears.

1. B → A → C
2. A → B → C
3. C → B → A
4. A → C → B

Answer: (b) A → B → C