For photoelectric emission from certain metals, the cutoff frequency is \(\nu\). If radiation of frequency \(2\nu\) impinges on the metal plate, the maximum possible velocity of the emitted electron will be:
(\(m\) is the electron mass)

1. \(\sqrt{\frac{h\nu}{m}}\) 2. \(\sqrt{\frac{2h\nu}{m}}\)
3. \(2\sqrt{\frac{h\nu}{m}}\) 4. \(\sqrt{\frac{h\nu}{2m}}\)

Subtopic:  Einstein's Photoelectric Equation |
 83%
From NCERT
AIPMT - 2013
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Light of two different frequencies, whose photons have energies of 1 eV and 2.5 eV respectively, illuminates a metallic surface whose work function is 0.5 eV successively. The ratio of maximum speeds of emitted electrons will be:

1.  1:2

2.  1:1

3.  1:5

4.  1:4

Subtopic:  Einstein's Photoelectric Equation |
 74%
From NCERT
AIPMT - 2011
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A 5 W emits monochromatic light of wavelength 5000 Å. When placed 0.5 m away, it liberates photoelectrons from a photosensitive metallic surface. When the source is moved 1.0 m away, the number of photoelectrons liberated is reduced by a factor of?

1. 4

2. 8

3.16

4. 2

Subtopic:  Electron Emission |
 71%
From NCERT
AIPMT - 2007
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When the light of frequency \(2\nu_0\) (where \(\nu_0\) is threshold frequency), is incident on a metal plate, the maximum velocity of electrons emitted is \(v_1\). When the frequency of the incident radiation is increased to \(5\nu_0,\) the maximum velocity of electrons emitted from the same plate is \(v_2.\) What will be the ratio of \(v_1\) to \(v_2\)?

1. \(1:2\) 2. \(1:4\)
3. \(4:1\) 4. \(2:1\)
Subtopic:  Einstein's Photoelectric Equation |
 72%
From NCERT
NEET - 2018
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An electron of mass m with an initial velocity \(\vec v= v_0\hat i\)\( ( v_o > 0 ) \) enters in an electric field \(\vec E = -E_0 \hat i\)\((E_0 = \text{constant}>0)\) at \(t=0\). If \(\lambda_0\)\(\lambda_0\), is its de-Broglie wavelength initially, then what will be its de-Broglie wavelength at time \(t\)?
1. \(\frac{\lambda_0}{\left(1+ \frac{eE_0}{mv_0}t\right)}\)
2. \(\lambda_0\left(1+ \frac{eE_0}{mv_0}t\right)\)
3. \(\lambda_0 t\)
4. \(\lambda_0\)

Subtopic:  De-broglie Wavelength |
 67%
From NCERT
NEET - 2018
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The figure shows different graphs between stopping potential V0 and frequency (\(\nu\)) for the photosensitive surfaces of cesium, potassium, sodium and lithium. The plots are parallel. The correct ranking of the targets according to their work function first will be:
   

1. (i) > (ii) > (iii) > (iv) 
2. (i) > (iii) > (ii) > (iv)
3. (iv) > (iii) > (ii) > (i) 
4. (i) = (iii) > (ii) = (iv)

Subtopic:  Photoelectric Effect: Experiment |
 74%
From NCERT
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The value of stopping potential in the following diagram is given by:
   

1. – 4 V 2. – 3 V
3. – 2 V 4. – 1 V
Subtopic:  Photoelectric Effect: Experiment |
 90%
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If in a photoelectric experiment, the wavelength of incident radiation is reduced from 6000 Å to 4000 Å, then:

1. The stopping potential will decrease.
2. The stopping potential will increase.
3. The kinetic energy of emitted electrons will decrease.
4. The value of the work function will decrease.

Subtopic:  Photoelectric Effect: Experiment |
 75%
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The stopping potential for photoelectrons:

1. does not depend on the frequency of the incident light.
2. does not depend upon the nature of the cathode material.
3. depends on both the frequency of the incident light and the nature of the cathode material.
4. depends upon the intensity of the incident light.
Subtopic:  Photoelectric Effect: Experiment |
 72%
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A photocell is receiving light from a source placed at a distance of 1 m. If the same source is placed at a distance of 2 m, then the ejected electron:

1. moves with one-fourth of energy as that of the initial energy.
2. moves with one-fourth of momentum as that of the initial momentum.
3. will be half in number.
4. will be one-fourth in number.
Subtopic:  Electron Emission |
 65%
From NCERT
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