Question

A photo-multiplier has $12$ plates including photo cathode and anode. Assume each dynode doubles the electrons. If a $10W$ source of $300nm$ is placed $2m$ away then the photocurrent shown by the photomultiplier tube is: (The dark current is $160\mu A$. Assume efficiency $10\%$ and flux reaching the photo-cathode is ${10}^{-4}$ of the original)

• A. $160\mu$
• B. $6.1mA$
• C. $5.94mA$
• D. $16.1\mu A$

Answer 1

The correct option is C $5.94mA$