Why audio signals cannotbe transmitted directly into space ?

How many different signals can be transmitted by arranging 3 red, 2 yellow and 2 green flags on a pole ?

For a CE-transistor amplifier, the audio signal voltage across the collected resistance of 2 k omega is 2 V. Suppose the current amplificationfactor of the transistor is 100, find the input signal voltage nd base current, if the base resistance is 1 k omega .

Why Fluorination of benzene not possible directly ?

Why should not we see directly towards the Sun?

11 kW of electric power can be transmitted to a distant station at (i)220 V. (ii) 22000 V. Which of the two transmission modes be preferred and why ? Support your answer with calculations.