Question

c sine wave with phase shift d. none of the above The following questions pertain to the circuits shown below. 3mA 15 M2 6 mA ? 330MS In an amplifier design, your company has a non-ideal current source. The amplifier acts like a resister of 15MA but can only take 3mA as input or it will overheat and cease function. It was discovered in testing that the above schematic delivered 4mA to the amplifier and most of the amps burned out. Over 1000 of these amps have already been built with such tight space requirements that there is only enough room for one component to be placed in parallel with the amplifier (5pts) 16. You are asked to redesign the above schematic so that the 1000 amplifiers that have been already produced can be used. The best scheme is a. put a resistor in parallel with the amplifier b. put an inductor in parallel with the amplifier c. put a capacitor in parallel with the amplifier d. put an oscilloscope in parallel with the amplifier Page 4 of 5

Answer 1

Answer -

   To limit the current, the best scheme is to put a resistor in parallel with the amplifier.

   The value of the resistor is selected such that the current in the 15 M$\small \Omega$ resistor is 3 mA.

Let the value of the parallel resistor be R.

If we apply the current divider rule, then,

   $\small \frac{2R}{3R+30}\times 6=3$

So,

   R = 30 M$\small \Omega$

So, we have to put a 30 M$\small \Omega$ resistor in paralle with the amplifier.

Hence, option (a) is correct.