(b) Explain the physical significance of this quantity for the propagation of radio waves in the Earth's upper atmospher

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B Explain The Physical Significance Of This Quantity For The Propagation Of Radio Waves In The Earth S Upper Atmospher 1 (82.02 KiB) Viewed 46 times

(b) Explain the physical significance of this quantity for the propagation of radio waves in the Earth's upper atmosphere, and calculate the plasma frequency at an altitude of 300 km if there are 4 x 1011 free electrons per cubic metre there. (2 marks) (C) Calculate the plasma frequency for copper stating any assumptions you make. The electrical conductivity of copper is 5.76 x 10'N-?m-?, its density is 8.9 x 103 kg m-3 and its atomic mass is 63.5 u. (2 marks) (d) When the same pulsar is observed at 300 MHz and 900 MHz, it is found that the low frequency signal is delayed by 0.1 s with respect to the high frequency signal. If the delay is caused by the presence of electrons in the intervening space, calculate the number of electrons per m_column in the line of sight. (3 marks)