Question

Determine the voltage input to the inverting terminal of an op-amp when -40 μvolts is applied to the non-inverting terminal and the output through an open-loop gain of 150,000 is 15 volts.

a) -50 μvolts

b) -35 μvolts

c) -25 μvolts

d) -30 μvolts

Answer 1

The calculated voltage input to the inverting terminal of the op-amp is -140 microvolts, which is not among the provided answer choices.

Step-by-step explanation:

We are asked to determine the voltage input to the inverting terminal of an operational amplifier (op-amp) given certain conditions. The op-amp has an open-loop gain (A) of 150,000, and the non-inverting terminal is supplied with -40 microvolts (μV). The output voltage (Vout) is 15 volts (V).

The behavior of an op-amp in an open-loop configuration can be described by the formula:

• Vout = A(V+ - V-)

Where V+ is the voltage at the non-inverting terminal, and V- is the voltage at the inverting terminal.

Given the output voltage (Vout) and the gain (A), we can rearrange the formula to solve for V-:

• V- = V+ - (Vout / A)

Plugging in the values we have:

• V- = -40 μV - (15 V / 150,000)
• V- = -40 μV - 0.0001 V
• V- = -40 μV - 100 μV
• V- = -140 μV

Therefore, none of the choices given (a) -50 μV, (b) -35 μV, (c) -25 μV, (d) -30 μV matches the calculated value of -140 μV. The correct answer is not listed among the options provided.