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106. A transformer has 450. turns in its primary coil and 150. turns in its secondary coil.  If the primary coil has 240. volts and 18.0 amps, what is the potential and current in the secondary coil.
      
A. 80.0 volts and 6.00 amps
B. 80.0 volts and 54.0 amps
C. 720. volts and 6.00 amps
D. 720. volts and 54.0 amps
     
Step down transformers have fewer turns in the secondary coil than the primary coil.  The transformer above has 150 turns in the secondary coil to 450 turns in the primary coil.
      

Vprimary       Vsecondary 
------------- = ---------------
Nprimary       Nsecondary  

     
                       Vprimary  x Nsecondary        240. volts x  150 turns
Vsecondary = -------------------------------- = --------------------------------- =  80.0 volts
                                  Nprimary                               4505 turn

        
Pprimary  =  Psecondary       P = IV

IprimaryVprimary  =  IsecondaryVsecondary  

     
                     IprimaryVprimary      18.0 amps x 240. volts
Isecondary = ----------------------- = ------------------------------ =  54.0 amps   The Correct Answer is B.
                          Vsecondary                     80.0 volts