FE Exam Practice Problem | Op Amp Gain

[@TJTJGAMERS]

Love your stuff keep it up!!!

[@studycat2658]

Thank you so much:)

[@evanmartin8199]

In your Eqn 2 above, why doesn't the 2 you divide thru by appear in the middle eqn as R4 / 2R3?

[@suprememaster1951]

Mind helping with this simple question? Question: To amplify input signal of v1(t) = 0.01×sin(2π×10kHz×t) using an inverting amplifier with gain of -10, determine the minimum required GBW for the opamp.

[@studycat2658]

GBW is found by multiplying the absolute value of the voltage gain times the cut off frequency. So it'd be the gain (10) times cut off frequency (10kHz) giving you 100 kHz.

[@suprememaster1951]

​@@studycat2658 awesome! Thank you for your clarification!

[@sathish2174]

Good stuff, please make videos on transistors also??

[@studycat2658]

Thanks! I have a couple videos on transistors on my channel if you want to check them out. Is there a specific topic you're looking for?

[@frankreiserm.s.8039]

Great video. I am an electronics technician not an engineer. I have been going on job interviews for electronics technician jobs but I have been getting tests requiring me to answer questions such as the one in this video. Why is that? Frank

[@studycat2658]

I suppose you are being tested on your knowledge. Circuit analysis is a good skill to have whether you're an engineer, a technician or an electrician. Thanks for watching!

[@suprememaster1951]

what does k mean though?

[@studycat2658]

K represents the gain of the bottom op-amp, which is an inverting amplifier. The gain expression of the inverting amplifier is given by: K = - R4 / R3 where R3 is the resistor connected between the input and the negative terminal of the op-amp, and R4 is the feedback resistor connected between the output and the negative terminal of the op-amp. In the given circuit, R3 = 5kΩ and R4 = 25kΩ, therefore: K = - R4 / R3 = -25kΩ / 5kΩ = -5 The magnitude of the gain is given by the ratio of the feedback resistor to the input resistor, which in this case is equal to 5. Hope that helps, thanks for watching!

[@suprememaster1951]

@@studycat2658 awesome thank you!