Merge pull request #176 from msaf9/master

ohms law implementation

DIRECTORY.md

@@ -90,6 +90,9 @@
   * [Ones And Zeros](https://github.com/TheAlgorithms/Ruby/blob/master/dynamic_programming/ones_and_zeros.rb)
   * [Pascal Triangle Ii](https://github.com/TheAlgorithms/Ruby/blob/master/dynamic_programming/pascal_triangle_ii.rb)
 
+## Electronics
+  * [Ohms Law](https://github.com/TheAlgorithms/Ruby/blob/master/electronics/ohms_law.rb)
+
 ## Maths
   * [3Nplus1](https://github.com/TheAlgorithms/Ruby/blob/master/maths/3nPlus1.rb)
   * [Abs](https://github.com/TheAlgorithms/Ruby/blob/master/maths/abs.rb)

electronics/ohms_law.rb

@@ -0,0 +1,31 @@
+# A ruby program for Ohms Law, which is used to calculate Voltage for the given Resistance and Current.
+# Ohms Law -> V = I * R
+# Reference: https://en.wikipedia.org/wiki/Ohm's_law
+
+def ohms_law(i, r)
+  if(i > 0 && r > 0)
+    "The voltage for given #{i} ampheres current and #{r} ohms resistance is #{r * i} volts."
+  else
+    raise
+  end
+  rescue
+    "Error: Please provide valid inputs only!"
+end
+
+# Valid inputs
+puts(ohms_law(5, 10))
+# The voltage for given 5 ampheres current and 10 ohms resistance is 50 volts.
+puts(ohms_law(2.5, 6.9))
+# The voltage for given 2.5 ampheres current and 6.9 ohms resistance is 17.25 volts.
+puts(ohms_law(0.15, 0.84))
+# The voltage for given 0.15 ampheres current and 0.84 ohms resistance is 0.126 volts.
+
+# Invalid inputs
+puts(ohms_law(5, -10))
+# Error: Please provide valid inputs only!
+puts(ohms_law(-5, -10))
+# Error: Please provide valid inputs only!
+puts(ohms_law(5, "10"))
+# Error: Please provide valid inputs only!
+puts(ohms_law("a", 10))
+# Error: Please provide valid inputs only!