The current conduction in a discharge tube is due to:
1.  electrons only
2.  +ve ions and –ve ions
3.  –ve ions and electrons
4.  +ve ions and electrons

Subtopic:  Photoelectric Effect: Experiment |
From NCERT
AIPMT - 1999
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If a light of amplitude A and wavelength λ is incident on a metallic surface, then the saturation current flow is proportional to (assume cut-off wavelength = ${\lambda }_{0}$):

1. ${A}^{2},$ $if$ $\lambda$ $>$ ${\lambda }_{0}$

2. ${A}^{2},$ $if$ $\lambda$ $<$ ${\lambda }_{0}$

3. $A,$ $if$ $\lambda$ $>$ ${\lambda }_{0}$

4. $A,$ $if$ $\lambda$ $<$ ${\lambda }_{0}$

Subtopic:  Photoelectric Effect: Experiment |
58%
From NCERT
AIPMT - 1999
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A photo-cell is illuminated by a source of light, which is placed at a distance $$d$$ from the cell. If the distance becomes $$\frac{d}{2}$$, then the number of electrons emitted per second will be:
1. same
2. four times
3. two times
4. one-fourth

Subtopic:  Photoelectric Effect: Experiment |
71%
From NCERT
AIPMT - 2001
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When ultraviolet rays strike a metal plate, the photoelectric effect does not occur. It occurs by the incidence of:

1. Infrared rays

2. X-rays

4. Lightwave

Subtopic:  Photoelectric Effect: Experiment |
66%
From NCERT
AIPMT - 2002
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A photoelectric cell is illuminated by a point source of light 1 m away. When the source is shifted to 2 m then:

 1 each emitted electron carries one-quarter of the initial energy 2 number of electrons emitted is half the initial number 3 each emitted electron carries half the initial energy 4 number of electrons emitted is a quarter of the initial number
Subtopic:  Photoelectric Effect: Experiment |
66%
From NCERT
AIPMT - 2003
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