Answer to Question #256705 in C++ for Dion Martins

Question

Students in Computer Science would like to understand the concept of Ohm’s law. You are required to write an application that will allow them to calculate the relation between Voltage, Current and Resistance using the formulas below.

V = IR, Current (I) = V/R, Resistance= V/I, (where I is the current, V - Voltage and R is the resistance). The program must do the following:

 Prompt the user for the calculation he/she would like to see or N/n to exit .

 Based on the option selected by the user (I/I, V/v, R/r),

1. The user must be prompted for the related data
2. The program must then calculate the related measurements based on the option selected.
3. Display the desired measurement.

 If an invalid option is selected an appropriate error message must be displayed.

NB: Use a switch for the selection  If there are no calculations to performed, display a summary that consist of the number of calculations performed. This number must exclude the invalid options,

Answer 1

SOLUTION TO THE ABOVE QUESTION

SOLUTION CODE

#include <iostream>
using namespace std;

//lets define fiunctioms to perform our operations
	//A function to calculate Voltage(V)=IR
	void voltage()
	{
		cout<<"\n\tEnter the value of Current(I): ";
		double I;
		cin>>I;
		cout<<"\n\tEnter the value of Resistance(R): ";
		double R;
		cin>>R;
		//calculate the volatge
		double V = I*R;
		cout<<"\tThe Voltage(V) = "<<V<<" Volts"<<endl;
	}
	
	//A function to calculate Resistance (R)= V/I
	void resistance()
	{
		cout<<"\n\tEnter the value of Voltage(V): ";
		double V;
		cin>>V;
		
		cout<<"\n\tEnter the value of Current(I): ";
		double I;
		cin>>I;
		
		//calculate the resistance
		double R = V/I;
		cout<<"\tThe Resistance(R) = "<<R<<" ohms"<<endl;
	}
	
	//A function to calculate Current(I)=V/R
	void current()
	{
		
		cout<<"\n\tEnter the value of Voltage(V): ";
		double V;
		cin>>V;
		
		cout<<"\n\tEnter the value of Resistance(R): ";
		double R;
		cin>>R;
		
		//calculate the current
		double I = V/R;
		cout<<"\tThe Current(I) = "<<I<<" amperes"<<endl;
	}


int main()
{
	
	//Now lets code the menu
	cout<<"\n\tEnter the operation to perform: "<<endl;
	cout<<"\tV/v.Calculate Voltage"<<endl;
	cout<<"\tR/r.Calculate Resistance"<<endl;
	cout<<"\tI/i.Calculate Current"<<endl;
	cout<<"\tN/n.Exit the program"<<endl;
	cout<<"\n\tEnter your option: ";
	char option;
	cin>>option;
	switch(option)
	{
		case 'V':
			//call voltage function
			voltage();
			break;
		case 'v':
			//call voltage function
			voltage();
			break;
		case 'R':
			//call resistance function
			resistance();
			break;
		case 'r':
			//call resistance function
			resistance();
			break;
		case 'I':
			//call current function
			current();
			break;
		case 'i':
			//call current function
			current();
			break;
		case 'N':
			cout<<"\n\tProgram successfully exited"<<endl;
			break;
		case 'n':
			cout<<"\n\tProgram successfully exited"<<endl;
			break;
		default:
			cout<<"\nYou have entered an Invalid option, please try again"<<endl;
	}


}

SAMPLE PROGRAM OUTPUT