Question

which of the following measurement tools would be useful in studying circuits that produce magnetic fields?
atomic clock
stopwatch
x-ray machine
compass

Explanation:

An atomic clock measures time with extreme precision, a stopwatch measures elapsed time, and an x-ray machine uses high-energy radiation to image internal structures. A compass uses a magnetic needle that aligns with magnetic fields; when near a circuit producing a magnetic field, the compass needle will deflect, making it useful for studying such circuits.

Answer:

compass