Solve the Problem $E$ , That Can Be Placed Across a Resistor Is Given

Solve the problem.
-The maximum number of volts, $E$ , that can be placed across a resistor is given by the formula $E = \sqrt { P R }$ , where $\mathrm { P }$ is the number of watts of power that the resistor can absorb and $\mathrm { R }$ is the resistance of the resistor in ohms. Solve this equation for $R$ . Use the result to determine the resistance of a resistor if $P$ is $\frac { 1 } { 2 }$ watts and $E$ is 10 volts.

A) $\mathrm { R } = \frac { \mathrm { E } ^ { 2 } } { \mathrm { P } } ; 200 \mathrm { ohms }$
B) $\mathrm { R } = \frac { \mathrm { E } ^ { 2 } } { \mathrm { P } ^ { 2 } } ; 400$ ohms
C) $\mathrm { R } = \mathrm { E } ^ { 2 } \mathrm { P } ; 200 \mathrm { ohms }$
D) $\mathrm { R } = \mathrm { E } ^ { 2 } \mathrm { P } ^ { 2 } ; 400 \mathrm { ohms }$