Question
help....
Calculate the cutoff frequency of the low pass filter shown in the figure. The answer must be to the nearest integer. RC Low Pass Filter 15789 Hz 10615 Hz 33163 Hz 22587 Hz An amplifier has an input signal power Pin = 20 UW. The output power Pout = 50 mW. What is the gain in dB for the amplifier at that frequency? +34 -23 +13 -33 A tank circuit coil has quality factor Q = 150. At what frequency f res can we use this coil if we need a bandwidth of 20 kHz? 3 MHz 10 MHz 20 KHz 2 MHz An amplifier has a power gain of 20 dB and an input signal power Pin= 100 mW. What is the output power level? 100 W 10 W 1. 0 W 100 mW An AC RLC series/parallel circuit consists of R = 2 k Ohm in parallel with a combination of L = 100 mH and C = 2 mu F in parallel. The circuit input impedance at resonance is 0 Ohm 2 k Ohm infinity Ohm Negative reactance
Explanation / Answer
1) 1/2*pi*R*C=15789 hz
2)33.97dB=34 dB
3)20*150=3 MHz
4)10W
5)2kohm
explanations: 1) f=1/2*pi*R*C=15789 hz
2)10log(pout/pin)=10log(50000/20)=34 dB
3)f= Q*BW=20*150= 3 Mhz
4)20=10log(pout/100mW). So pout=10W
5)In resonance,1/w*c equals to w*L. So impedance will be equal to R only. Ans: 2 kohm
