Experimental arrangement for the photoelectric effectप्रकाश-विद्युत प्रभाव के अध्ययन की प्रायोगिक व्यवस्थाExperimental arrangement for the photoelectric effect

NCERT Fig 11.1 · Class 12 Physics · Chapter 11 · interactive diagram

Parts and what they mean

• Evacuated glass/quartz tube (निर्वातित काँच/क्वार्ट्ज़ नली) — Air is removed so that electrons travel from C to A without colliding with gas molecules.
• Quartz window W (क्वार्ट्ज़ खिड़की W) — Ordinary glass absorbs ultraviolet; quartz lets UV through to reach plate C.
• Light source S (प्रकाश स्रोत S) — Gives monochromatic light of short wavelength. Frequency is changed with coloured filters; intensity by changing the distance of the source.
• Incident light (आपतित प्रकाश) — Falls on the photosensitive plate C through window W.
• Emitter C (photosensitive plate) (उत्सर्जक C (प्रकाश-सुग्राही प्लेट)) — Thin photosensitive plate; electrons are emitted from it when light of suitable frequency falls on it.
• Collector A (संग्राहक A) — Collects the photoelectrons. Its potential relative to C can be made positive (accelerating) or negative (retarding).
• Photoelectrons (प्रकाश-इलेक्ट्रॉन) — Electrons emitted by C and moving towards A; their flow is the photocurrent.
• Voltmeter (वोल्टमीटर) — Measures the potential difference between emitter C and collector A.
• Microammeter (माइक्रोऐमीटर) — In series; measures the (very small) photoelectric current.
• Commutator (दिक्परिवर्तक) — Reverses the polarity of plates C and A, so A can be made negative with respect to C.
• Potential divider (rheostat) (विभव विभाजक (धारा नियंत्रक)) — With the battery across it, the sliding contact picks off a variable voltage between C and A.
• Sliding contact (सर्पी संपर्क) — Moving it changes the potential difference applied between the plates.
• Battery (बैटरी) — Long thin line = positive terminal. In this setting its + side makes A positive with respect to C.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 11.1. Report a mistake