Ohm's law is given by the equation v = ir where v is voltage in watts, i is current in amperes, and r is resistance in ohms. a lamp needs 0.5 amperes. which equation can be used to determine the voltage for a given amount of resistance? v=0.5r v=r0.5 v = 0.5r v = 2r

You start with the equation V = IR, plug the value 0.5 for I and you have

V = 0.5*R

So, the first three options are equivalent and correct.

V=IR

And current, Ampere is given as 0.5 so substituting it back in the main equation gives V = 0.5R

i think the answer is seven, for if i'm being useless °ω°

step-by-step explanation: