Light of frequency 1.5 times the threshold frequency is incident on a photosensitive material. What will be the photoelectric current if the frequency is halved and intensity is doubled ?

1. doubled

2. four times

3. one-fourth

4. zero

Doubtly Asked 30 Oct 2026 NEET UG 2020 Practice test neet Save WhatsApp Report

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Answer: 4. zero

Photoelectric emission needs frequency \(\nu\ge\nu_0\), whatever the intensity.

Initially \(\nu=1.5\nu_0\). Halved, it becomes \(0.75\nu_0<\nu_0\), below threshold.

No electrons are emitted, so the photoelectric current is zero, even though intensity is doubled. Answer: option 4.

Doubtly AI · 30 Oct 2026 AI-generated · not yet verified Report

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