Microwave telephonic link operating at the centre frequency of 10 GHz has been established. If 4 % of this is available for microwave communication channel, then no channels can be granted. If each telephone is allotted a bandwidth of 8 kHz is  $P\times {10}^3$ then P is

Microwave frequency used  = 10 GHz
                                                       $=10\times {10}^9$Hz
                                                       $={10}^{10}$ HZ
 Total band width of channel = 4 % of  ${10}^{10}$
                                                          $=4\times {10}^8$  HZ
    Band width per channel    $=8\times {10}^3$  HZ
                             No of channels  $=\frac{Total band width}{Band width per channel}$ 
                                                              $=\frac{4\times {10}^8}{8\times {10}^3}=0.5\times {10}^5=50\times {10}^3$