Voltage used by an electrical device is , where is the voltage in volts, is the power in watts, and is the resistance in ohms.

The function .

(**a**)

Find power consumption of the lamp.

Voltage.

Resistance.

Solve for .

Consider .

.

Substitute the values of and in above equation.

watts.

The power consumption of the lamp is watts.

(**b**)

Find the resistance of the DVD player.

Current .

Power watts.

Solve for .

Consider .

Substitute the values of and in above equation.

The resistance of the DVD player is .

(**c**)

**Ohms law :**

Ohms law states that the current through a conductor between two points is directly proportional to the potential difference across the two points.

Ohms law expresses voltage in terms of current and resistance. The two functions are and .

Solve for .

Consider .

Substitute in equation (1).

(**a**) The power consumption of the lamp is watts.

(**b**) The resistance of the DVD player is .

(**c**) .

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