the two terminals of a metallic spring are connected to a battery and tap key in series.when the key is pressed how the spring works?
Answers
A wire is essentially an extremely low-Ohm resistor. The battery itself has some internal resistance that will limit the current flow (it can’t be infinite, after all). So the maximum available current from the battery will flow through the wire and back to the battery. Power is I^2*R, so even if R is very small, the current will still be significant and so will be the power - and all that power does is make heat.
The wire will get hot.
The battery will get hot.
Depending on the chemistry of the battery, it may catch on fire and/or explode. The wire may melt.
My brother, an auto mechanic once accidentally grounded the positive terminal of a starter motor to the frame of a car he was working on. A 12-Volt car battery has VERY low internal resistance, and the wrench he grounded through turned cherry-red in less than a second. He managed to break the circuit before anything caught on fire, but that wrench was ruined. The palm of his hand where he’d been gripping the wrench didn’t look all that great for a few weeks, either.