Answer: D

 

189. Picture A in fig.27 represents input signal of the filter circuit. Define the type of the filter applied if the result of filtration process is shown in picture C as output voltage?

 

 

Fig.27

A).low-pass filter B).high-pass filter C). band-pass filter

D). stop-band filter E). band-reject filter

Answer: C

190. What i-v characteristic corresponds to the ideal current source? Picture_____

A B C D E

 

 

A).A B).B C).C D).D E).E

Answer: A

191. How many filter prototypes do you know?

A).2 B).3 C).4 D).5 E).6

Answer: C. They are low-pass filter, high-pass filter, band-pass filter, stop-band (band-reject) filter

192. How many equations does it need to prepare if we solve the circuit in fig. 28 applying mesh-current analysis?

 

 

Fig.28

A)1 B).2 C).3 D).4 E).5

Answer: A, because two mesh-currents are equal to currents of the sources and are known already.

 

193. For the circuit below R₁=R₂=100Ω, R₃=50 Ω. What is the value of R_A?

 

 

A). 100 Ω B). 200 Ω; C). 300 Ω D). 400 Ω E). 250 Ω

Solution:

R_a = (R₁R₂ + R₂R₃ + R₃R₁) / R₁ = (100*100 + 100*50 + 100*50) / 100 = 100 + 50 + 50 = 200 Ω.

Answer: B

 

194. Three inductors of 2 mH, 3 mH, and 6 mH are connected in parallel. What is equivalent inductance of the circuit?

A).1 mH B)2 mH C).3mH D).4 mH E). 5 mH

Solution:

=> L = 1 mH

Answer: A

 

 

195. For picture C in fig.29 C1=50nF, R1=10kΩ, C2=20nF, R2=20kΩ. Define cutoff frequency for the case.

 

 

Fig.29

A).100H B)198Hz C).250Hz D).300Hz E).356Hz

Solution:

 

Hz

Answer: E

 

196. For low-pass filter R=2.2 kΩ, C=50 nF. What is cutoff frequency for the filter?

A).0.5 kHz B)0.85 kHz C).1.1 kHz D)1.45 kHz E)2.05 kHz

Solution:

Hz