UGC NET CSE | December 2010 | Part 2 | Question: 28

Question

How much bandwidth is there in $1$ micron of spectrum at a wavelength of $1$ micron ?

• A. $300$ MHz
• B. $3$ GHz
• C. $300$ THz
• D. $30$ KHz

Answer 1

C: 300THZ. The formula is $\Delta f = c * \Delta \Lambda / \Lambda^{2}$ where ∆f is the bandwidth range, c is the light speed, $\Delta \Lambda$ is the wavelength range and $\Lambda$ is a certain wavelength.

For frequency to be in hertz and speed of light in meter/second, we want the wavelength to be in meters.

As 1 meter = 1000,000 microns, calculating using the formula you get 300 THZ.