Hello!
We can use the following equation for calculating power dissipated by a resistor:
[tex]P = i^2R[/tex]
P = Power (? W)
i = Current through resistor (2.0 A)
R = Resistance of resistor (50Ω)
Plug in the known values and solve.
[tex]P = (2.0^2)(50) = \boxed{\text{ B. }200 W}[/tex]
