A radar operating at 5 GHz uses a common antenna for transmission and reception. The antenna has a gain of 150 and is aligned for maximum directional radiation and reception to a target 1 km away having radar cross-section of 3m². If it transmits 100 kW, then the received power (in $$\mu W$$) is ______ .

The injected excess electron concentration profile in the base region of an npn BJT, biased in the active region, is linear, as shown in the figure. If the area of the emitter-base junction is 0.001 cm², µ_n = 800 cm²/(V-s) in the base region and depletion layer widths are negligible, then the collector current I_c (in mA) at room temperature is __________. (Given: thermal voltage V_T = 26 mV at room temperature, electronic charge q = $$1.6\times10^{-19}\;C$$ )

Consider the charge profile shown in the figure. The resultant potential distribution is best described by

The figure shows the I-V characteristics of a solar cell illuminated uniformly with solar light of power 100 mW/cm². The solar cell has an area of 3 cm² and a fill factor of 0.7. The maximum efficiency (in %) of the device is __________.