Electrical Power Formula:
Over-all Equations for V, I, R and P
Problems:
1. From the equation of Power
(P)
Prove that P
�2
=
�
������ (�����)
, is equal to P
���
=
��
=
�
2. From the equation of Current (I)
Prove that I
�
=
�
, is equal to I
�������
=
���
=
�
�
3. From the equation of Resistance (R)
�
Prove that R
R=
= �2
������ (�����)(���.)
, is equal to
�������2
=
�.�.�
�2
4. A barbeque electric grill having element resistance of 2 ohms will draw
how much current when connected to a 230 V source ?
5. A 20 kΩ resistor has 40 mA of current flowing through it. What is the value
of the applied voltage.