Answer:
Gold is not used for making electric wires because it is too rare, and too costlier than Copper. Silver and copper are used for making wires. Copper is almost used in electric lines
Answer:
W = 0
Explanation:
We are given with, a construction worker is carrying a load of 40 kg over his head and is walking at a constant velocity. He travels a distance of 50 m.
The work done by an object is given by :

F = ma
So,

m is mass
a is acceleration
d is displacement
The worker is moving with constant velocity, its acceleration will be 0. So, the work done by the worker is 0.
-6.98 × 10-^7 is the answer <3
In the outer layers of earths atmosphere gases are in ionized state primarily on account of cosmic rays . as earth rotates , strong electric current are set up due to movement of ions . these currents form earth magnetic field . and thus two equal and opposite poles of earth formed