Answer Happy

4.2 Noninverting Amplifier (4-3) — The circuit in Figure 4.2 uses a potentiometer whose total resistance is R1. The movable stylus on terminal 2 creates two variable resistors: BRį be- tween terminals 1-2 and (1 – B)Rį between terminals 2–3. The movable stylus varies ß over the range 0 <B<1. 1. Obtain an expression for G = vo/v, in terms of ß. 2. Calculate the amplifier gain for B 0.0, B = 0.5, and B = 1.0 with component values R1 10 kN and R2 1.5 kΩ. 3. Let vs be a 100-Hz sinusoidal signal with a 1-volt peak value. Plot vo and v, to scale for ß = 0.0, B = 0.5, and B = 1.0. Us = — - = = Vs Vo 1 2 R1 3 M R2 = Figure 4.2: Circuit for Problem 4.2 NI Multisim Measurements 1. Enter the circuit of Figure 4.2 into NI Multisim. Use these specific components: OPAMP_3T_VIRTUAL, AC_VOLTAGE, and virtual linear potentiometer; see the video tutorial below to learn how to search for parts by name. Set the AC voltage source frequency to 100 Hz. 2. Observe vs and v, with the oscilloscope. Vary the potentiometer value over its full range of 0 to 100%, and then use the oscilloscope cursors to measure the circuit gain for ß = 0.0, B = 0.5, and B 1.0. — = 3. Print screen shots of the oscilloscope for B 0.0, B = 0.5, and B 1.0. Use the same Channel A and Channel B vertical scale (volts per division) for all three screen shots. Additional helpful tips: • Use the Simulate + Instruments + Oscilloscope with vs on Chan- nel A and v. on Channel B. Run an interactive simulation until several cycles of oscillation appear on the oscilloscope display. • Use the cursors to measure the peak values of the input and output signals, and then calculate the amplifier gain as the output value di- vided by the input value. NI Multisim video tutorials: • Find components by name: • AC (sinusoidal) voltage source: • Basic operation of the two-channel oscilloscope: • Waveform cursor measurements with the two-channel oscilloscope: