Answer to Question #61363 in Electricity and Magnetism for bebeji

Question

11) An air-cored transformer is assumed to be 100% efficient. The ratio of the secondary turns to the primary turns is 1:20. A 240V ac supply is connected to the primary coil and a 6Ê load is connected to the secondary coil. what is the current in the primary coil?
a) 0.10A
b) 0.14A
c) 2.0A
d) 40.0A

12) A voltmeter connected across a 60Hz ac source reads 240V. Write down the expression of the instanteneous voltage as a function of time.
a) 240sin339.4t
b) 339.4sin377t
c) 377cos339.4t
d) 240cos339.4t