7 fill in the blank 2 points if distance is halved, how much is the beam intensity affected? would image…

7 fill in the blank 2 points if distance is halved, how much is the beam intensity affected? would image density increase or decrease?
Answer
Explanation:
Step1: Recall the inverse - square law
The intensity $I$ of a beam is inversely proportional to the square of the distance $d$ from the source, i.e., $I=\frac{k}{d^{2}}$ where $k$ is a constant.
Step2: Change the distance and find new intensity
Let the initial distance be $d_1$ and intensity be $I_1=\frac{k}{d_1^{2}}$. If the distance is halved, so $d_2 = \frac{d_1}{2}$. Then the new intensity $I_2=\frac{k}{d_2^{2}}=\frac{k}{(\frac{d_1}{2})^{2}}=\frac{k}{\frac{d_1^{2}}{4}} = 4\times\frac{k}{d_1^{2}}$. So $I_2 = 4I_1$.
Step3: Determine effect on image density
Since beam intensity is related to image density (higher intensity means more photons hitting the imaging surface per unit area), and the intensity has increased, the image density will increase.
Answer:
The beam intensity is quadrupled. Image density increases.