Photoelectric threshold frequency ν₀ = φ/h. If work function doubles, ν₀: MCQ with Answer and Explanation

Photoelectric threshold frequency ν₀ = φ/h. If work function doubles, ν₀:
A. Quadruples
B. Halves
C. Unchanged
D. Doubles
Answer: Option D
Solution (By JKExamLibrary)
ν₀ ∝ φ. Double work function ⇒ double threshold frequency. Higher φ requires higher photon energy for emission. Memory tip: 'ν₀ = φ/h; larger φ ⇒ higher frequency needed'. Photoelectric effect relation frequently tested in competitive quantum physics sections.

This question belongs to: Science Physics

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Physics Questions

Question #1 Report Error
A wave of frequency 500 Hz has speed 350 m/s. Wavelength is
A. 70 m
B. 0.7 m
C. 1.43 m
D. 175 m

Correct Answer: Option B


Explanation:
λ = v/f = 350/500 = 0.7 m.

This question belongs to: Science Physics
Question #2 Report Error
Capacitor charging work stored as:
A. Heat
B. Electrostatic energy
C. Magnetic energy
D. Chemical energy

Correct Answer: Option B


Explanation:
Work done stored in electric field between plates: U = ½CV². Recoverable on discharge. Memory aid: 'Capacitor energy = ½CV² in electric field'. Electrostatics concept frequently tested in competitive exams.

This question belongs to: Science Physics
Question #3 Report Error
A lactometer is used to:
A. Measure humidity
B. Measure liquid density
C. Measure wind speed
D. Measure milk purity

Correct Answer: Option D


Explanation:
Lactometer is a specialized hydrometer for measuring milk purity/density. It works on Archimedes' principle: pure milk has specific density; adulteration (with water) changes density, altering lactometer reading. While it measures density, its specific application is milk testing. Option B is partially correct but not specific; competitive exams expect the precise application. Memory tip: 'Lacto = milk; meter = measure'. This application-based question tests knowledge of scientific instruments in daily life, frequently appearing in competitive exams. Always note context-specific uses of general instruments.

This question belongs to: Science Physics