Question

Find the thevenin’s equivalent for resistance and voltage?

(a) 1-iii, 2-ii, 3-1

(b) 1-ii, 2-I, 3-iii

(c) 1-I, 2-ii, 3-iii

(d) 1-ii, 2-iii, 3-i

I had been asked this question in final exam.

The query is from Input Offset Voltage in chapter Operational Amplifier Fundamentals of Linear Integrated Circuits

Answer 1

The answer to this question cannot be provided directly without more context, such as the specific circuit diagram you're referring to. The options you provided appear to be labeling choices related to the components of Thevenin’s equivalent circuit — which involves finding the Thevenin equivalent resistance (RthR_{th}Rth​) and voltage (VthV_{th}Vth​).

In general:

• Thevenin’s Voltage (VthV_{th}Vth​) is the open-circuit voltage across the terminals where the load will be connected.
• Thevenin’s Resistance (RthR_{th}Rth​) is the resistance seen from the terminals when all independent sources are turned off (voltage sources replaced by short circuits, current sources replaced by open circuits).

To find these values:

1. To find VthV_{th}Vth​, calculate the open-circuit voltage across the two terminals.
2. To find RthR_{th}Rth​, deactivate all independent sources (voltage sources become shorts, current sources become opens) and calculate the equivalent resistance seen from the two terminals.