Chapter 26, Problem 68MSPP

Halogen Bulbs

Halogen bulbs have some differences from standard incandescent lightbulbs. They are generally smaller, the filament runs at a higher temperature, and they have a quartz (rather than glass) envelope. They may also operate at lower voltage. Consider a 12 V, 50 W halogen bulb for use in a desk lamp. The lamp plugs into a 120 V, 60 Hz outlet, and it has a transformer in its base.

How much current is drawn by the lamp at the outlet? That is, what is the rms current in the primary?

A. 0.42 A

B. 1.3 A

C. 4.2 A

D. 13 A