A light of wavelength $$\lambda$$ is incident on the metal surface and the ejected fastest electron has speed $$v.$$ If the wavelength is changed to $$\frac{3\lambda}{4},$$ then the speed of the fastest emitted electron will be:

 1 smaller than $$\sqrt{\frac{4}{3}}v$$ 2 greater than $$\sqrt{\frac{4}{3}}$$$$v$$ 3 $$2v$$ 4 zero

Subtopic:  Einstein's Photoelectric Equation |
69%
From NCERT
AIPMT - 1998
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The work function of a metal surface is φ = 1.5 eV. If a light of wavelength 5000 Å falls on it, then the maximum K.E. of the ejected electron will be:

 1 1.2 eV 2 0.98 eV 3 0.45 eV 4 0 eV
Subtopic:  Einstein's Photoelectric Equation |
80%
From NCERT
AIPMT - 1998
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Light of wavelength $$3000 ~{\mathring{\mathrm{A}}}$$ in Photoelectric effect gives electron of maximum kinetic energy $$0.5 ~\text{eV}$$. If the wavelength changes to $$2000 ~{\mathring{\mathrm{A}}}$$ then the maximum kinetic energy of emitted electrons will be:

 1 less than $$0.5 ~\text{eV}$$ 2 $$0.5 ~\text{eV}$$ 3 greater than $$0.5 ~\text{eV}$$ 4 the photoelectric effect does not occur

Subtopic:  Einstein's Photoelectric Equation |
82%
From NCERT
AIPMT - 1999
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What did Einstein prove by the photo-electric effect?

1. E = h$$\nu$$

2. $KE=\frac{1}{2}m{v}^{2}$

3. $E=m{c}^{2}$

4. $E=\frac{-Rh{c}^{2}}{{n}^{2}}$

Subtopic:  Einstein's Photoelectric Equation |
60%
From NCERT
AIPMT - 2000
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The value of Planck's constant is:

1. $6.63×{10}^{-34}$ $\mathrm{J}/\mathrm{s}$

2. $6.63×{10}^{-34}$ $\mathrm{kg}-{\mathrm{m}}^{2}/\mathrm{s}$

3. $6.63×{10}^{-34}$ $\mathrm{kg}-{\mathrm{m}}^{2}$

4.

Subtopic:  Einstein's Photoelectric Equation |
58%
From NCERT
AIPMT - 2002
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According to Einstein's photoelectric equation, the graph between the kinetic energy of photoelectrons ejected and the frequency of incident radiation is:

 1 2 3 4
Subtopic:  Einstein's Photoelectric Equation |
77%
From NCERT
AIPMT - 2004
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The work functions for metals A, B, and C are respectively 1.92 eV, 2.0 eV, and 5 eV. According to Einstein's equation, the metals that will emit photoelectrons for a radiation of wavelength 4100 Å is/are:
1. None
2. A only
3. A and B only
4. All the three metals

Subtopic:  Einstein's Photoelectric Equation |
78%
From NCERT
AIPMT - 2005
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A photosensitive metallic surface has a work function of hν0. If photons of energy 2hν0 fall on this surface, the electrons come out with a maximum velocity of 4 × 106 m/s. When the photon energy is increased to 5hν0, then the maximum velocity of photoelectrons will be:

1. 2 ×107 m/s

2. 2 × 106 m/s

3. 8 × 105 m/s

4. 8 × 106 m/s

Subtopic:  Einstein's Photoelectric Equation |
77%
From NCERT
AIPMT - 2005
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