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.