What is the gain expression for a differential amplifier when V1 is grounded?

What is the gain expression for a differential amplifier when V1 is grounded?

• A. Gain = Vo/V2
• B. Gain = V2/Vo
• C. Gain = (1 + R1/R2)(Vn)
• D. Gain = (R2+R1)/(Vn)

Answer: (A)

In a differential amplifier, the output voltage is a result of the difference between two input voltages, usually referred to as V1 and V2. When V1 is grounded, it essentially becomes zero volts. This simplifies the analysis of the circuit since the gain expression will only depend on the input voltage V2. For a differential amplifier, the output voltage (Vo) can be expressed in terms of the two input voltages. With V1 grounded (V1 = 0V), the output voltage is primarily influenced by V2. The gain of the amplifier can be understood as the ratio of the output voltage Vo to the input voltage V2. Hence, the gain expression can be simplified to reflect this relationship: Gain = Vo/V2. This specific gain expression is applicable as it directly correlates how much the differential amplifier amplifies the input signal (V2) relative to the output signal (Vo). This relationship is foundational in understanding how differential amplifiers work, particularly when one input is set to a fixed reference point, such as ground. This establishes why the first option is the correct gain expression when one of the differential amplifier's inputs is grounded.

In a differential amplifier, the output voltage is a result of the difference between two input voltages, usually referred to as V1 and V2. When V1 is grounded, it essentially becomes zero volts. This simplifies the analysis of the circuit since the gain expression will only depend on the input voltage V2.

For a differential amplifier, the output voltage (Vo) can be expressed in terms of the two input voltages. With V1 grounded (V1 = 0V), the output voltage is primarily influenced by V2. The gain of the amplifier can be understood as the ratio of the output voltage Vo to the input voltage V2. Hence, the gain expression can be simplified to reflect this relationship: Gain = Vo/V2.

This specific gain expression is applicable as it directly correlates how much the differential amplifier amplifies the input signal (V2) relative to the output signal (Vo). This relationship is foundational in understanding how differential amplifiers work, particularly when one input is set to a fixed reference point, such as ground.

This establishes why the first option is the correct gain expression when one of the differential amplifier's inputs is grounded.