A physicist wishes to measure the exposure of a beam of gamma rays. The beam is passed through 2.00× 10^-²kg of dry air at STP. The beam produces positive ions in the air which have a total charge of 3.87 × 10^-⁶C. What is the exposure (in roentgens) of the beam? A)7.74 × 10^-⁸R B)1.94 × 10^-⁴R C)3.25 × 10^-²R D)0.750 R E)1.25 R

Question

Quizplus · Accepted Answer

To calculate the exposure (X) in roentgens (R), we can use the following equation:

X = (1.293 × 10^-4 C/kg) * Q/m

Where Q is the total charge produced by the gamma rays in the air and m is the mass of the air that the gamma rays pass through.

We are given that Q = 3.87 × 10^-6 C and m = 2.00 kg.

Plugging in these values, we get:

X = (1.293 × 10^-4 C/kg) * (3.87 × 10^-6 C / 2.00 kg) 
X = 0.750 R

Therefore, the answer is D, 0.750 R.

A Physicist Wishes to Measure the Exposure of a Beam