# Homework Help: Doubts in modern physics photoelectric :mad: effect

1. Apr 2, 2006

### aytida88

i know theses qns may look lame but my answers are not matching with the book .pls help as i have a MAJOR EXAM coming up tomorrow

1.three photons are coming out from an excited ample of hydrogen atoms with energies of 12.1 10.2 and 1.9 eV respectively then which of the following is true?these photons must come from
1.1 atom
2.2 atoms
3.3 atoms
4.2 or 3 atoms

whats the logic here???:yuck:

2.A hydrogen atom in ground state absorbs 10.2 eV of energy.the orbital moment of it's electron will increase by...........
1.05x10^-34
2.11x10^-34
3.16x10^-34
4.22x10^-34

3.x ray from a coolidge tube is incident is incident on a aluminium foil(very thin).the intensity of the x ray transmitted is found to be I0
the heating current is increased as ro increase the temperature of the filament.the intensity of x ray transmitted will be
1.zero
2.<I0
3.>I0
4.=I0

4.:yuck: :MOST IMP DBT
The frequency and intensity of light source are doubled then which of the following statement(s) is/are true.....
1.saturation current remains unchaged
2.maximum kinetic energy is doubledd
answer is a is true b is false
5.this one is also urgent
a point source causes photoelectric effect from a small metal plate .which of the following graphs best represents the relation between the photo current and distance....
the graph given is a rectangular hyperbola in the first quadrant.....
how??

2. Apr 2, 2006

### Hootenanny

Staff Emeritus
You can start by giving use your answers and working. And by the way, question one is a completely legitimate question, think about how many electrons each hydrogen atom has and what are the energy states of a hydrogen atom.

-Hoot