EGR203 Electric and Electronic Circuits Assignment 8

  1. For the circuit shown below, answer the questions below. Assume that RC = 1 kΩ, RB = 10 kΩ, VCC = 12 V, VCE = 0.3 V at saturation, VBE = 0.7 V, and β = 50.

    1. Find iC if VBB = 0.5 V.
    2. Find iC if VBB = 2.0 V.
    3. Find iC if VBB = 3.5 V.
    4. Find VBB required to saturate the transistor.

  2. Given the following circuit, with R1 = 200 kΩ, R2 = 50 kΩ, RC = 4 kΩ, and RE = 1 kΩ. Assume VCC = 15 V, the voltage drop VBE = 0.7 V and the transistor β = 200. Find VE, iC, Vo, V2, and iB.

  3. Solve the previous problem in Multisim assuming first a 2N3904 transistor and then a 2N2222A transistor.

  4. Given the following circuit, in which RC = 3 kW, β = 80, VBE = 0.7 V, VCE = 8 V, and VCC = 15 V. Find iC and the value of RB.

  5. Suppose we have two Aluminum foil sheets (250 mm by 250 mm square) with a 12-µm thick food wrap dielectric (estimated relative dielectric constant of 2.5). Calculate the capacitance.

  6. Given two capacitors, one of 15 µF and the other 30 µF. Find the effective capacitance if the capacitors are connected in series (end-to-end) and if they are connected in parallel (side-by-side).

  7. A voltage of 50 V appears across a 10-µF capacitor. Determine the amount of charge and the energy stored on the capacitor.

  8. Suppose the time-varying voltage across a capacitor C = 10 µF is V = 20 sin(200t). Find the time-varying current.

  9. Show that the units of RC are seconds, given that C = Q/V and R = V/I.

Maintained by John Loomis, last updated 28 March 2011