ISRO Scientist or Engineer Electronics 2012
Instructions
For the following questions answer them individually
Question 51
The RF amplifier A is having 3 dB NF & 5 dB ofgain, amplifier B is having 3.5 dB NF & 15 dB. For overall noise figure of the cascaded system, the correct statementis :
Question 54
In a uniform linear array, four isotropic radiating elements are spaced $$\frac{\lambda}{4}$$ apart. The progressive phase shift between the elements required for forming -
the main beam at $$60^\circ $$ of the end fireis:
Question 55
The radiation resistance of a thin line centre fed A/2 antenna with sinusoid currentdistributionis :
