NCERT Solutions for Class 5th The World Around Us Chapter 7 Rubber Band Guitar — Activity 2
Book page 117 Updated on2026-09-19
Q1.
Rubber Band Guitar — 1. Make a hole on the top of a cardboard box. 2. Stretch rubber bands around the box and across the hole. 3. Place a ruler or pencil under the bands at one end to raise them. 4. Pluck the bands and listen to the sounds produced.
Answer
What you will hear: each band gives a clear twanging note. You can see the band blur as it shakes to and fro. The sound comes out much louder because of the box, and the moment you stop the band with your finger, the sound stops too.
How to make it:
Take an empty cardboard box — a shoe box or a tissue box works well.
Cut a round hole, about the size of your palm, in the middle of the top face.
Stretch four or five rubber bands around the box so that they pass right over the hole.
Push a pencil or a ruler under all the bands near one end. This lifts the bands off the box.
Pluck one band — pull it up a little and let it go.
Listen. Then pluck the others one by one.
Rubber bands stretched over a box with a hole, raised at one end by a pencil.
Why it happens: When you pluck a band, it starts to shake to and fro very fast. That fast shaking is called vibration. The vibrating band shakes the air around it, and that shaking air reaches your ear — and you hear a sound. The book says it plainly: plucking the rubber bands makes them vibrate and produce sounds, and this is known as sound energy. The hole and the hollow box make the sound louder, because the air inside the box shakes along with the band. That is why a real guitar, a sitar and a dholak are all hollow.
Check it yourself: Pluck a band and touch it gently with your finger. Two things happen at once — you feel the shaking, and the sound stops. No vibration, no sound.