Question

In the circuit shown above, an input of 1V is fed into the inverting input of an ideal Op-amp A. The output signal \(V_{out}\) will be

• A. +10V
• B. -10V
• C. 0V
• D. infinity

Hint:

For an inverting op-amp: \(V_{out} = -\left(\frac{R_f}{R_{in}}\right)V_{in}\). The minus sign shows phase reversal.

Answer 1

The Correct Option is B

Step 1: Identify the configuration.
The non-inverting terminal of op-amp is grounded, and input is applied through a resistor to the inverting terminal.
So the circuit is an inverting amplifier.
Step 2: Write gain formula for inverting amplifier.
\[ V_{out} = -\left(\frac{R_f}{R_{in}}\right)V_{in} \]
Step 3: Substitute resistor values from diagram.
From figure:
\[ R_{in} = 1k\Omega,\quad R_f = 10k\Omega,\quad V_{in} = 1V \]
Step 4: Calculate output.
\[ V_{out} = -\left(\frac{10k\Omega}{1k\Omega}\right)(1V) = -10V \]
Final Answer:
\[ \boxed{-10V} \]