1. Suppose that the modulating signal is m(t) = 2cos (2pfmt) and the carrier signal is xC(t) = AC cos(2pfct), which one of the following is a conventional AM signal without over modulation?
Options
A. x(t) = Acm(t)cos(2pfct)
B. x(t) = Ac [1 + m(t)]cos (2pfct)
C.
D. x(t) = Accos(2pfmt)cos(2pfct) + Acsin(2pfmt)sin(2pfct)
2. The electric field on the surface of a perfect conductor is 2V/m. The conductor is immersed in water with ? = 80 ?0. The surface charge density on the conductor is ((?0 = 10-9/36p)F/m)
7. An SCR is triggered at 80° in the positive half cycle, only. The rms anode current is 25 A. If the firing angle is changed to 160°, the rms current is likely to be
8. The fixed count that should be used so that the output register will represent the input for a 6 bit dual slope A/D converter uses a reference of -6v and a 1 MHz clock. It uses a fixed count of 40 (101000).