Analog Electronics Which of the following oscillators is suitable for frequencies in the range of megahertz? RC phase shift Wien bridge Hartley Both (a) and (c) None In a half-wave rectifier, if an a.c supply is 60 Hz. Then what is the a.c ripple at the output? 30 Hz 50 Hz 60 Hz 10Hz None The ac output voltage vac is 0.2cos(ωt)mV cos(ωt)mV 2cos(ωt)mV 22cos(ωt)mV None To protect the diodes in a rectifier and capacitor input filter circuit it is necessary to use surge resistor surge inductor surge capacitor both (a) and (b) None The load impedance ZL of a CE amplifier has R and L in series. The phase difference between output and input will be 180° 0 more than 90° but less than 180° more than 180° but less than 270° None In a BJT circuit, a PNP transistor is replaced by an NPN transistor. To analyze the new circuit all calculations are done earlier have to be repeated replace all calculated voltages by reverse values replace all calculated currents by reverse values replace all calculated voltages and currents by reverse values None For common emitter input characteristics is 6V and is changed from 0.32 to 0.8V also base current changes from 40μA to 60μA, then by using the given data calculate the input impedance (in KΩ ) kept constant. 4KΩ 20KΩ 24KΩ 30KΩ None To prevent a DC return between source and load, it is necessary to use resistor between source and load inductor between source and load capacitor between source and load either (a) or (b) None In a 741 Op-Amp, there is 20 dB/decade fall-off starting at a relatively low frequency. This is due to the Power load Impedance Source Internal Compensation Power Dissipation in the chip None For a base current of 10 μA, what is the value of collector current in common emitter if βdc = 100 1μA 10μA 1mA 10 mA None
