A 12 V, 60 W lamp is connected to the secondary of a step-down transformer, whose primary is connected to AC mains of 220 V. Assuming the transformer to be ideal, what is the current in the primary winding?
0.37 A
0.27 A
2.7 A
3.7 A
According to the sources, for an ideal transformer, the power input to the primary is equal to the power output from the secondary () . The power consumed by the lamp in the secondary circuit is given as 60 W. Therefore, the power in the primary circuit is also 60 W. Using the power formula , we can find the primary current () by dividing the primary power by the primary voltage: A, which rounds to 0.27 A.
Join thousands of students and practice with AI-generated mock tests.