What device increases voltage? A. generator
B. motor
C. step-down transformer
D. step-up transformer

Your answer would be C.

A step-up transformer is a transformer that raises voltage from main to secondary by having more secondary winding turns than primary winding turns.

Hope this helps; have a great day!

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach

0.93xc=0.93x3x10^8m/s

2.54cm is 1 inch

360seconds i 1 hr