hi just needed to know if the power dissipated by a resistor is equal to the total voltage. I am having a hard time understanding a problem i was given, and i know the formulas to find power dissipated, but i can't use P = I squared * R or P = V squared / R for this question... " A 10 ohm resistor dissipates 1 W of power when connected to a dc voltage source. If the value of dc voltage is doubled, the resistor will dissipate?" My teacher said the answer is 4 watts, but he never actually worked it out for me, and i would like to know how he got that answer, rather than just believe him. How do i find the power dissipated if i'm not given the voltage? Is the 1W of power dissipated by the 10 ohm resistor equal to my total Voltage? As you can see this problem is driving me crazy, and i've been stuck and not sure how to figure it out. Someone PLEASE help me out!! It is probably not as hard as i am making it, but thanks in advance.