Question 18: a
question 19: b
question 20: c
Answer:
the correct answer is option C
Answer:
10 feet.
Explanation:
Conductors are considered outside the building when they installed. The requirement of NEC is above 10 feet for the clearance after the final grade for service conductors and cables where they are connected with the building, above the sidewalks and the to other areas which are accessible to the pedestrians.
Answer:
3400 m
Explanation:
Both lightning and thunder happen at the same time but one is faster than the other. The distance traveled by a sound can be calculated from its speed such that;
speed = distance/time, hence, distance = speed x time.
<em>For a thunder with 340 m/s speed and 10 seconds away from lightning, the distance between the thunder and the lightning can be calculated as</em>;
distance = 340 m/s x 10 s = 3400 m