Which parts make up an electromagnet?
A coil of 50 turns is wound on a soft-iron core, and a current is switched on. The electromagnet's tip holds 4 steel screws. The same wire is wound on again: 50 extra turns, 100 turns in all, same current, same core. Now the tip holds 9 steel screws.
Only one thing changed between the two tries: the number of turns. Every turn adds its own field, and the fields add together.
Extra turns are wound onto an electromagnet's coil, same current and core. What happens to its field?
A third of the turns are unwound, current and core unchanged. What happens to the field?
An electromagnet's coil is rewound from 80 turns to 160 turns, with the same current and core. What happens to its field strength?
More turns make a stronger electromagnet.
160 turns are more than 80 turns.
Its field gets stronger.
Turns are removed from an electromagnet's coil, current and core unchanged. What happens to its field strength?
Fewer turns make a weaker electromagnet.
Its field gets weaker.
An electromagnet grew stronger; its current and core never changed. What changed?
Which change makes an electromagnet stronger?
Two electromagnets share one current and identical cores: one with 40 turns, one with 200 turns. Which holds more steel washers?
An electromagnet is rewound from 120 turns down to 40, same current and core. What happens to the number of steel tacks it holds?