1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

A-Level Physics Help Required

  1. Nov 9, 2009 #1
    Last year I sat my physics A-Level paper and despite achieving A's in the first 3 modules I took a nosedive and underachieved. I have finished school now and am retaking modules in January time and upon my preparation I have come across a few problems which I can't seem to answer! Any help would be greatly appreciated. Here goes:

    1) Explain the problem and state how the measurement can be made more accurate when measuring the fringe width in Young's Double Slit experiment (laser/monochromatic light source)

    2) Explain how the following formula follows from the definition of intensity:
    I= P/(4 x pi x r2)

    3) Photoelectical Emission:
    (i)When p.d is set to zero the microammeter indicates a small current. Why?

    (ii) The cathode is made from sodium - work function 3.7 x 10^-19 J. Show the stopping potential for radiation of frequency 7.5 x 10^14 Hz is approx 0.8V

    (iii) Sketch a graph to show how current changes as the reverse potential difference V is increased from 0 to 1.0 V

  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted

Similar Discussions: A-Level Physics Help Required