V = voltage. 1 0 obj endobj 3 0 obj While Ohm’s law defines the relationship between resistance, voltage, and current in a circuit; … If they are in line they are multiplied, but if one is on top of the other then they should be divided. Again, this arrangement represents the actual position of each quantity within the Ohms law power … x��[�s�6����ձi @�_3i���m��777IdY�x�DU���/���]�Aji��ӵ3�E�.v?��۪x��*��7/�j:[������r������ͻ�c��VE���k�ͫ���ˋ��K!M쬸}���"��ቓ��"Ke���vuy��G ���L�ɵL���q��ˋ� ��Tgd*�c��2��$�د���R*��@���NL����ar�Fb�����b.ޕ�k�[zr;I�m1�6�t=�V�#~��w�nVJU�4\I����T4:N@E�Ԧ5㋉��l^2�~b�-.=���y��Q���S�����ח�p��٬ 3f{���v_��]ˎ Therefore: .343 amps x 12 volts = 4.116 watts of power. *NOTE: Ohm’s Law works all the time with DC (direct current) circuits, but only works with AC L҉��Ld���s��ɓ-y�� People often ask; what is the difference between Watt’s law and Ohm’s law? Now that we have calculated the amperage (I), we can plug the answer into the formula to find watts (P). <>>> [ P = V x I ] P (watts) = V (volts) x I (amps) Also: [ P = V 2 ÷ R ] P (watts) = V 2 (volts) ÷ R (Ω) Also: [ P = I 2 x R ] P (watts) = I 2 (amps) x R (Ω) Again, the three quantities have been superimposed into a triangle this time called a Power Triangle with power at the top and current and voltage at the bottom. (746 Watts = 1 Horsepower) Power is measured in Watts and is symbolized by the letter P. Power (Watts) equals Energy (joules) divided by time (seconds). %PDF-1.5 �o�Y���DG{�2�����3�������6M*�1�H�d�V���EQ1؂����-w%,�;�:�4��c�#ؓ���9. Watt's Law defines another of the most fundamental relationships in electronics. We can not go very much farther into electronics until these concepts are understood. In the power triangle, we find that amps (I) times volts (E) = watts (P). Two things you need to determine: What amperage capacity relay to use. ���)ƙG�;����-��,�&&�NXP܌�X�R�m@�|�&�! *;�06�[yǘ� �p�Z�MJ�=گ 0�0�Uh��D����Ϡu��B�7��c�Fʵ���S�g���� D�l�:I�A��h�sJJM�]T.���Ȝ��tla 0)�x�R&Ok��k�6����͒-��c�d���j~��I3�5�GE={FH��D��hg��׿O���cm�fp9C����ſ˽X ��9�b5��+��9�{?�hW��a��)�f@G���Z@F��v�� 4 0 obj That is the relationship between power and the quantities defined by Ohm's law. In other words if current has … Ohm's Law defines one of most fundamental relationships in electronics. What size wire to run from the relay to the headlights. You have selected bulbs that are rated 65 watts. <> m����_ They will make you ♥ Physics. endobj Recommended for you Where: I = current. That is the relationship between Voltage, Current, and Resistance. %���� The unit of power is joule per second (J/sec) also known as watts (W). Watt's Law Example: Calculate Amps from Watts and Voltage - Adding an Accessory You are setting up a truck with a snow plow and want to add plowing lights. stream <>/ExtGState<>/XObject<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> <> Lectures by Walter Lewin. P = power. This is sometimes known as the Ohm's law triangle. Watt’s law formula. The formula for Watt’s law is: P=IV. power triangle. In the top corner of the Ohms law triangle is the letter V, in the left hand corner, the letter I, and in the right hand bottom corner, R. To use the triangle cover up the unknown quantity and then and then calculate it from the other two.