A metal wire of resistance R is cut into five equal pieces that are then placed together side by side to form a new cable with a length equal to one-fifth the original length. What is the resistance of this new cable

R / 25

Explanation:

Let the initial length of the wire is L and its resistance is R.

Now the length is cut into 5 equal parts.

The resistance of a wire is directly proportional to the length of the wire, thus, the resistance of each portion of the wire is R/5.

Now the five pieces are connected in parallel combination, the equivalent resistance is

Thus, the resistance of the new cable is R / 25.

96.77 amp

explanation:

rl = 250/100 = 2.5 ohms.

egl = 250 + (100 × 0.1) + 2 = 262 v.

at 700 r.p.m., eg2 = 262 × 700/1000 = 183.4 v.

if ia is the new current, then eg2 - 2 - (ia × 0.1) = 2.5 ia

which means this will give ia = 96.77 amp.