To find the value of the secondary voltage, we can use the turn ratio of the transformer. The turn ratio is the ratio of the number of turns in the secondary winding to the number of turns in the primary winding.
In this case, the turn ratio is given as 10. Since the primary voltage is 120 V, we can calculate the secondary voltage by multiplying the primary voltage by the turn ratio.
Secondary voltage = Primary voltage x Turn ratio
Secondary voltage = 120 V x 10
Secondary voltage = 1200 V
Therefore, the value of the secondary voltage is 1200 V (option a).