Question

An X-Ray tube operates at a potential of $100kV$ and $10mA$ tube current. If only $1$% of the electrical power is converted into X-Rays, the rate at which the target is heated is:

• A. $99W$
• B. $990W$
• C. $100W$
• D. $1000W$

Answer 1

The correct option is B $990W$

Power $=VI$
$=100\times {10}^3\times 10{\times }^{-3}$
$=1000$ watt
Now 1 % of power is converted into X -Rays so, 99%
goes for heating
So, heating rate = $99$% of $1000$ watt
= $\frac{99}{100}\times 1000watt$
$=990$ watt