# Instructions for the Ohm's Law and Power Calculator

## Objectives

• to understand Ohm's Law and Power equations.
• to master metric prefix conversion.
• to understand how to get common metric prefixes into calculators.
• to aid in understanding how to convert word based problems into numerical solutions.

## Controls

Random selects a random question with two random numbers and random notation.

Calculate calculates the two unknowns based on the two known numbers.

Check checks answers (+/- 1%) entered from keyboard.

Undo undoes the last entry for corrections.

Clear clears the four inputs. Sig. Figs. and Notation are not changed.

Problem Set selects a course content problem (Workbook or Assignments).

Sig. Figs. controls the number of significant figures used. Default: 3.

Notation controls the numerical notation used. Recommend Engineering Notation.

• Standard Form - Decimal Numbers (0.000125).
• Scientific - Scientific Notation (1.25e-4).
• Engineering - Engineering Notation (125µ). Multiples of 3.
• Eng (calc) - Formulas show Engineering Notation converted to external calculator buttons/functions (125[Exp]-6).
• Concentrate on this setting. Learn how to get the metric system into your calculator.

## General Instructions

The best way to learn how the calculator works would be to just play with it. But to get the most out of the calculator as a learning tool, the following instructions may help you.

To work, the calculator requires any two of the four inputs. Then the calculator can be used in a number of ways.

• Calculate button will calculate the unknowns.
• Check button will check your answers entered by keyboard.

Calculator started by:

• Entering two numbers with keyboard.
• Random button.
• Select a problem from the problem set.

Numbers can be input as decimal numbers (Standard Form), Scientific Notation, Engineering Notation or metric prefixes. For example 125µA can be entered as 0.000125, 1.25e-4, 125e-6, 125 u or 125u (the letter u is used for micro - µ - Greek letter mu). All other metric prefixes for electrical units are standard keyboard characters.

• T - Tera e+12.
• G - Giga e+9.
• M - Mega e+6.
• k - kilo e+3.
• m - milli e-3.
• µ - micro e-6 (u).
• n - nano e-9.
• p - pico e-12.

Using a metric prefix on input converts the calculator to Engineering Notation.

The schematic circuit will always use metric prefixes because this is the format you must master.

The format used in the Question will not change to get you used to the different notations.

Notation settings will change calculator and formula content. Try different settings until you master how to put the metric system (Engineering Notation) and Scientific Notation into your calculator.