Warmup

How are a voltage source and a capacitor different?

How are a resistor and an open switch similar?

WarmupStart work on your circuits practice packet. Have out your Waves Lab writeup for collection if not already turned in, plus Ch. 34 notes.

Warmup - Circuit Diagram SymbolsVoltage Source Wire Meter

Resistor Capacitor Inductor

Switch (closed) Switch (open) Ground

Warmup1) What is different about an electric circuit system and an electrostatic system?

2) How does a transformer work?

Warmup

Which circuit elements can store energy in some form or another?

Which circuit elements rely on resistance in order to function?

What decimal value does the binary number 01100110 have?

VocabularyConcept Variable Unit Label Definition

Voltage V Volts (V) How hard the electrical field is pushing electrons

Current I Amps (A) (coloumbs/s)

How many electrons flow per second

Resistance R Ohms (Ω) How easily the material allows the electrons to move

Power P Watts (W) (coloumbs * volts/ s)

Work done per second

Charge q Coloumbs (C) 6.24×1018 electrons or protons

Inductance L Henries (H) How much a current affects (and stores potential energy) in magnetic fields

Capacitance C Farads (F) (coloumbs/volt)

How much charge can be built up as a result of a voltage

Circuits Practice

April 11, 2012

Circuits Practice 1Design a circuit that could produce a magnetic field of two different strengths.

Circuits Practice 2Design a circuit that could take a 9V battery and produce a 4.5V source for something.

Circuits Practice 3Design a circuit which uses two 2 Ω and one 5 Ω resistors to create a total of a 6 Ω resistance.

Circuits Practice 4Design a circuit which powers a 50W item, using 120V of potential, where the item has a resistance of 1.5 Ω.

Circuits Practice 5Design a circuit which sends 2A of current through one wire, and 1A of current through the other wire.

Circuit Practice 6Create a circuit diagram which charges a capacitor at 6V, using a 9V source, where the capacitor can create a burst of magnetic fields in either direction.

Circuit Practice 7Create a circuit which has a total resistance of 16,666 Ω using only 10,000 Ω resistors.

Circuit Practice 8Create a circuit which flips a magnetic field back and forth, which is called an electric motor.

Circuit Practice 9A circuit has two 4 Ω resistors in parallel, which are in series with a 2 Ω resistor. Draw the circuit and calculate the total resistance.

Circuit Practice 10Two 5 Ω resistors are in parallel. This is combined in series with a 6 Ω resistor and in series with three 6 Ω resistors in parallel. Draw the circuit. Calculate the combined resistance.

Transistors

Transistor Construction

Resistors Color CodeColor Sig.

figures Multiplier Tolerance Temp. Coefficient (ppm/K)

Black 0 ×100 – 250 U

Brown 1 ×101 ±1% F 100 S

Red 2 ×102 ±2% G 50 R

Orange 3 ×103 – 15 P

Yellow 4 ×104 (±5%) – 25 Q

Green 5 ×105 ±0.5% D 20 Z

Blue 6 ×106 ±0.25% C 10 Z

Violet 7 ×107 ±0.1% B 5 M

Gray 8 ×108 ±0.05% (±10%) A 1 K

White 9 ×109 – –Gold – ×10-1 ±5% J –

Silver – ×10-2 ±10% K –

None – – ±20% M –

To-do

Hands-on practice:1) Resistors in series2) Resistors in parallel3) Current through a circuit with a known resistance4) Voltage sources in series

Lab design:1) Choose circuit or electrostatic-based system2) Identify circuit elements needed to move object, or method to generate charge.3) Find resistances, calculate current, and see if voltage source can provide it.4) Troubleshoot anticipated problems with additional circuit elements.