Vacuum bell jar experimentनिर्वात बेल जार प्रयोग

NCERT Fig 10.7 · interactive diagram

Parts and their functions

• Bell jar (बेल जार) — An airtight glass jar — we can see the bell even when we cannot hear it.
• Electric bell (विद्युत घंटी) — Keeps ringing throughout; only the loudness we hear changes.
• To power supply (विद्युत आपूर्ति से) — Keeps the bell ringing.
• To vacuum pump (निर्वात पंप से) — Sucks air out. Sound becomes fainter; at near vacuum almost nothing is heard. Let air back in → sound returns.
• Air — the medium (वायु — माध्यम) — Sound needs a material medium. No medium (vacuum) → no sound. That is why astronauts use radio sets in space.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 10.7. Report a mistake