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NEET Photoelectric Effect PYQs (Last 10 Years) + Graph Questions

Graph showing kinetic energy vs frequency and current vs voltage in photoelectric effect for NEET physics students
Photoelectric Effect Graphs for NEET – KE vs Frequency & Current vs Voltage Explained



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NEET Mock Test - Photoelectric Effect

🔥 NEET Mock Test (Photoelectric Effect)

Q1. Stopping potential depends on?
A) Intensity B) Frequency C) Distance D) Area
Answer: B
Stopping potential depends on kinetic energy which depends on frequency.
Q2. If frequency equals threshold frequency, KE is?
A) Maximum B) Zero C) Infinite D) Constant
Answer: B
At threshold frequency, electron just escapes so KE = 0.
Q3. Work function depends on?
A) Frequency B) Material C) Intensity D) Temperature
Answer: B
Each metal has its own work function.
Q4. Increasing intensity will?
A) Increase KE B) Increase electrons C) Decrease KE D) No effect
Answer: B
Intensity increases number of photons → more electrons.
Q5. Photoelectric effect proves?
A) Wave B) Particle C) Both D) None
Answer: B
It proves particle nature of light.
Q6. Photon energy depends on?
A) Wavelength B) Frequency C) Intensity D) Time
Answer: B
E = hν.
Q7. Unit of work function?
A) Joule B) eV C) Both D) Watt
Answer: C
Work function can be expressed in Joule or eV.
Q8. Maximum KE depends on?
A) Intensity B) Frequency C) Work function only D) Area
Answer: B
KE = h(ν − ν₀).
Q9. No emission when?
A) ν < ν₀ B) ν = ν₀ C) ν > ν₀ D) Intensity low
Answer: A
Below threshold frequency, emission is not possible.
Q10. Slope of KE vs ν graph?
A) e B) h C) m D) c
Answer: B
Slope equals Planck's constant.
Q21. If ν = 2ν₀, KE is?
Answer: A
KE = h(ν − ν₀) = hν₀.
Q30. If wavelength increases, energy?
Answer: B
E ∝ 1/λ, so energy decreases.
Q31. Find energy for ν = 5×10¹⁴ Hz
Answer: 3.3×10⁻¹⁹ J
E = hν = 6.63×10⁻³⁴ × 5×10¹⁴
Q32. Work function = 4 eV, find ν₀
Answer: 9.6×10¹⁴ Hz
ν₀ = W₀/h
Q33. ν = 8×10¹⁴, ν₀ = 5×10¹⁴
Answer: 1.99×10⁻¹⁹ J
KE = h(ν − ν₀)
Q34. KE = 3.2×10⁻¹⁹ J
Answer: 2 V
eV = KE
Q35. λ = 400 nm
Answer: 4.97×10⁻¹⁹ J
E = hc/λ
Q41. Assertion: KE depends on intensity
Reason: More photons increase energy
Answer: False, True
Intensity increases number, not energy.
Q42. Assertion: Instantaneous emission
Reason: Energy transfer immediate
Answer: True, True
Photon transfers energy instantly.
Q45. Assertion: Light has dual nature
Reason: Wave + particle behavior
Answer: True, True
Light shows both properties.

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