Q1. Two slits are illuminated by a 621nm light. The angel between the zeroth-order bright band at the center of the screen and fourth-order bright band is 18degrees. The screen is 141cm from the double-slit. What is the distance between the two slits?
Q2. An ionization chamber was exposed to gamma rays and 2x10^12 ion pairs were produced per gram of CO2 (W=33 ev/ip). What was the absorbed dose in the carbon walls? The average mass stopping powers of graphite and CO2 for the photons are, respectively, 1.648 and 1.680 MeV cm^2/g