Answer:
Value of 
Explanation:
We have given
In first case resistance is 
and current is 1.8 A
Let the potential difference is v
So 
----eqn 1
In second case resistance is 
and current is 1.6 A and potential difference will be as it is a series connection
So 
----eqn 2
From eqn 1 and eqn 2
Answer:
d. f
Explanation:
Based on the principle of operation of transformer, when a.c voltage is applied at the terminal of the primary coil (input coil), an alternating magnetic flux is produced in the iron core which links the secondary coil (output coil).
Also, an alternating e.m.f of <em>the same frequency</em> as that of primary coil (input coil) <u>will be induced in the secondary coil (output coil) by mutual inductance.</u>
Thus, If the input frequency is "f" then the output frequency will be "f" (since the frequency will be the same).
The correct option is "D"
