Lab 7

© N. B. Dodge 01/12

Voltage Divider and Reducing Phase Shift Worksheet

1. Given the voltage divider circuit shown, with input voltage of 20V, R1 = 1KΩ and

R2 = 3KΩ, and RL = 20KΩ. Output voltage across R2 should be 15V, ±0.1V. Can

this voltage divider meet the specification as shown?

2. In the circuit below, if the inductive and capacitive impedances have the

same magnitude, since they are opposite in sign, they will cancel each other

out, and there will be no imaginary current in the circuit. That is, if we have:

𝑗ω𝐿 = 1

𝑗𝜔𝐶 ,

where 𝜔 = 2𝜋𝑓, L is the inductance in Henry’s, and C is the capacitance in Farads, then the current will be entirely a real number and the imaginary

impedance = 0. Based on this equation, solve for a value C as a function of

L and ω. You will use this formula in Lab.

3. In the circuit below, if 𝐿 = 20𝑚𝐻, find C such that 𝑗ω𝐿 = j

𝜔𝐶 , if the radian

frequency 𝜔, of the circuit is 1000 radians/second.

4. In the circuit above, if the signal frequency is 60 Hertz, what must C be to ensure

that the imaginary impedance sums to zero, given the same value of L?