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) 2×104 B) 2×103 C) 2×105 D) 2×106 Answer: Option CExplanation:Only 10% of 10 GHz is utillised for transmission. ∴ Band available for transmission = 10100×10×109Hz=109Hz Now, If there are n channels each using 5 kHz then, n×5×103=109 ⇒ n=2×105