How to Calculate Resistance, Power, and Energy in a Portable MP3 Player

Question 1:

What is the resistance of the portable MP3 player if it runs on a 1.5V battery and draws 5.7mA of current for six hours?

Question 2:

How much power is dissipated in the portable MP3 player?

Question 3:

What is the total energy delivered by the portable MP3 player?

Answer:

To calculate the resistance, power, and energy in a portable MP3 player, we can use the given values and basic formulas from electrical circuits.

First, let's convert the given values to S.I units for accurate calculations. The portable MP3 player runs on a 1.5V battery, draws 5.7mA of current (which is 5.7 x 10^-3 amps), and operates for six hours (which is 21600 seconds).

Resistance Calculation:

To find the resistance, we can use Ohm's Law which states V=IR. Rearranging the equation, we get:

Resistance = p.d / current

Resistance = 1.5 / 5.7x10^-3

Resistance ≈ 263.2 ohms

Power Calculation:

To calculate power, we can use various equations such as P=VI, P=I^2 R, P = V^2 / R, or P = E/T. Using P=VI:

Power = p.d x current

Power = 1.5 x (5.7x10^-3)

Power ≈ 8.55 x 10^-3 Watts

Energy Calculation:

To determine the energy delivered by the portable MP3 player, we can use the equation E=PT:

Energy = power x time

Energy = (8.55x10^-3) x 21600

Energy ≈ 184.68 joules

By calculating the resistance, power, and energy in the portable MP3 player, we gain a better understanding of its electrical characteristics and efficiency. These calculations can help optimize the device's performance and battery usage.