Instructions for Ohm's Law and Power Calculator

Objectives

• to allow the student to become familiar with the various forms of Ohm's Law and Power equations.
• to provide the student with practise in prefix conversion.
• to allow the student to become familiar with converting text based problems into numerical solutions.

The calculator can be used in a number of ways.

• Input two numbers into the calculator and press the Calculate button to calculate the two unknowns.
• Use the calculator to check your answers based on your own calculations. Once two numbers are inserted into the calculator, the Check button allows you to verify your own answers. This calculation can be initialized by:
  • Enter two numbers.
  • Press the Random button.
  • Select a problem from the problem set

Numbers can be input as decimal numbers or using scientific notation or engineering notation or prefixes. For example 125µA can be entered as 0.000125, 1.25e-4, 125e-6 or 125 u (the letter u is used for micro - µ. All other prefixes are standard keyboard characters).

The circuit shown always uses three significant figures and prefixes. This is the format you must be able to understand, so it is used on the circuit.

Controls

Random generates two random numbers and a random notation.

Check checks your answers. Use it to aid you in becoming familiar with the formulas. Once two numbers have been entered into the calculator, Check will check your answer against

Calculate calculates the two unknowns. Enter any TWO of the following values or press the Random button, then press the Calculate button.

Undo undoes the last calculation. This allows you to change numbers.

Clear clears the calculator.

Problem Set selects a problem from a written problem set and sets the calculator up to generate the answers.

Show Formulae shows either the Ohms Law/Power formulas or the formulas required to complete the calculation.

Significant Figures controls the number of significant figures the calculator uses. Recomment 3 or 4 significant figures. Pull down menu on the bottom of page.

Notation controls the notation the calculator uses. Recomment engineering or prefix notation. Pull down menu on the bottom of page.