# Help with electronics question. Urgent!

Discussion in 'Electronics Homework Help' started by sarah90, Aug 23, 2011.

1. ### sarah90

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Aug 23, 2011
Hi there Im a student, studying at college and I have an exam coming up and need help with this mock paper, but I have no idea because It is very hard for me, if you could do the calculations for me I could learn the methods and understand. thank you for you help. regards Sarah. I have attached the file on the website with the link below.

443
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Jun 10, 2011
Like you've been told elsewhere, show what you've done so far and someone might critique your work. Don't expect people to do your work for you. Besides, your question is exactly what you should have asked your instructor if you didn't understand the stuff in class.

3. ### Laplace

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184
Apr 4, 2010
1.(a) - Does the {gain x bandwidth} constant have any relevance here?

1.(a)(i) - Does a 20kΩ resistor to ground have the same impedance as a 20kΩ resistor to virtual ground?

http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/opampvar7.html#c1

1.(a)(iii) - Try using a current sensing resistor with the voltage across the resistor amplified by a difference amplifier. Select the value of the resistor and the gain of the amplifier so that 100 mA through the resistor causes 1 V output from the amplifier.

http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/opampvar5.html#c1
How would a weighted sum relate to digital binary DAC inputs?

http://www.maxim-ic.com/app-notes/index.mvp/id/810
No need to design the logic circuit; an input/output logic table should be more than sufficient.

2.(b) - Here is a good answer for you: