Question

A typical wall outlet voltage in the United States is 120 volts. Personal MP3 players require much smaller voltages, typically 487.0 mV 487.0 mV . If the number of turns in the primary coil is 2464 2464 , calculate the number of turns on the secondary coil of the adapter transformer.

Answer 1

Answer:

Number of turns on the secondary coil of the adapter transformer is 10.

Explanation:

For a transformer,

    $\frac{V_{s} }{V_{p} } = \frac{N_{s} }{N_{p} }$

where $V_{s}$ is the voltage induced in the secondary coil

           $V_{p}$ is the voltage in the primary coil

          $N_{s}$ is the number of turns of secondary coil

         $N_{p}$ is the number of turns of primary coil

From the given question,

    $\frac{487*10^{-3} }{120}$ = $\frac{N_{s} }{2464}$

⇒    $N_{s}$ = $\frac{2462*487*10^{-3} }{120}$

            = 9.999733

  ∴   $N_{s}$ = 10 turns

Answer 2

Answer:

607,145 turns

Explanation:

Output voltage, that is secondary voltage,Es = 120 volts

Input voltage, that is primary voltage, Ep = 487/1000 = 0.487 volts

Number of turns in secondary = Ns

Number of turns in primary, Np = 2464

∴ Es/Ep = Ns/Np

Ns = Es * Np/Ep = 1`20 X 2464/0.487 =  607,145 turns ( Step up transformer)