The gamma radiation field intensity equation is accurate to within how much percentage for gamma energies between 0.05 MeV and 3 MeV?

For distances in meters, what is the correct equation to determine the intensity?

What is the calculated exposure rate at 1 ft. for a 400-mCi 192 Ir which emits the following gammas: 0.316 MeV (87%), 0.486 MeV (52%), 0.308 MeV (32%), 0.295 MeV (30%)?

If more than one photon energy is given, how should the sum be taken?

What does the "curie/meter/rem" rule specify for Co-60?

How would you calculate the exposure rate at 2 meters for a 1.8 Ci point source of 60 Co that emits two gammas (1.173 MeV and 1.332 MeV) for every disintegration?

What would be the exposure rate at 10 ft for an 8 Ci point source of Co-60 that emits a 1.173 and 1.332 MeV gamma, both at 100% of the disintegrations?