Discussion Forum



1)

A telephonic communication service is working at carrier freequency of 10 GHz. Only 10% of it is utilised for transmission. How many telephonic channels can be transmitted simultaneously, if each channel requires a bandwidth of 5kHz?


A) $2\times 10^{4}$

B) $2\times 10^{3}$

C) $2\times 10^{5}$

D) $2\times 10^{6}$

Answer:

Option C

Explanation:

Only 10% of 10 GHz is utillised for transmission.

  $\therefore$      Band available for transmission

                        = $\frac{10}{100}\times 10 \times 10^{9}Hz =10^{9} Hz$

   Now, If there are n channels each using 5 kHz then,  $n \times 5\times 10^{3}=10^{9}$

       $\Rightarrow$                            $n =2\times 10^{5}$