Atomic and Nuclear Physics Answers

When a metallic surface is illuminated with light of wave length (lambda),the stopping potential is X volt.when the same surface is illuminated of wave length 2lambda, stopping potential is X/3 threshold wave length for the metallic surface is....

a monochromatic point source of light is placed at a distance d from a metal surface.plate electron are ejected at a rate n per sec with maximum kinetic energy E.if the source brought nearer to distance d/2, the rate and maximum kinetic energy per photo electric become...

Light frequency 1.5 times the threshold frequency is incident on photo sensitive material of the frequency is 1/2 and intensity become double.the photo electric current become....

reasons that why the electrons cannot reside in energy gap or forbidden band gap?

sir... why should we take shell K L M N letters in Neels bhors experiment not A B C D s

is shadow is a matter?

what are types of absorption coefficient?
what are the parameters which absorption coefficient dependence on?
Can make alpha, beta and gamma rays energies approaching to zero?

what is the maximuim energy resolution in percent necessary to resolve two peaks at 720 KeV and 755 KeV?

Radioactive isotopes used in cancer therapy have a "shelf- life," like pharmaceuticals used in chemotherapy. Just after it has been manufactured in a nuclear reactor, the activity of a sample of 60co is 5000 Ci. When its activity falls below 3500 Ci, it is considered too weak a source to use in treatment. You work in the radiology department of a large hospital. One of these 60co sources in your inventory was manufactured on October 6, 2004. It is now April 6, 2007. Is the source still usable? The half-life of 60co is 5.271 years.
a) What is the mass of the source when it was manufactured?
b) Is this source still useable?

(a) The 210Po source used in a physics laboratory is labeled as having an activity of 1.0μCi on the date it was prepared. A student measures the radioactivity of this source with a Geiger counter and observes 1500 counts per minute. She notices that the source was prepared 120 days before her lab. What fraction of the decays is she observing with her apparatus? (b) Identify some of the reasons that only a fraction of the α s emitted are observed by the detector.