2014 Med Phys I Lecture 4.1b PreTest Question Title * 1. Name: Question Title * 2. To obtain the collision kerma from the kerma, you Exclude the component due to Bremsstrahlung losses. Exclude the energy deposited outside the collection volume. Include the component due to Bremsstrahlung losses. Include the energy deposited outside the collection volume. Question Title * 3. Guard electrodes are required in a free-air ionization chamber to Collect all the secondary radiation produced in the collection volume. Ensure charged particle equilibrium. Ensure that electric lines of force are straight. Protect the collection volume from stray radiation. Question Title * 4. In measuring radiation using an ionization chamber, we generally need to make corrections for temperature and pressure because An ionization chamber defines a fixed volume, whereas exposure requires a fixed mass. An ionization chamber defines a fixed mass, whereas exposure requires a fixed volume. Exposure is only defined at Standard Temperature and Pressure. The amount of ionization varies with temperature and pressure. Question Title * 5. The purpose of the wall of an ionization chamber is to Attenuate the incident photons prior to measurement. Define a region where exposure can be measured. Ensure mechanical stability of the ionization chamber. Ensure that charged-particle equilibrium is achieved. Question Title * 6. Bragg-Gray Theory relates Absorbed dose in gas to ionization charge produced in a water cavity in the medium. Absorbed dose in a medium to ionization charge produced in a gas cavity in the medium. Absorbed dose in a medium to ionization charge produced in a water cavity in the medium. Absorbed dose in water to ionization charge produced in a gas cavity in the medium. Question Title * 7. Are there any issues that are not clear to you at this time? Done