Answer:
We can use optical fibers.
Explanation:
The optical fibers are the optical devices which is based on the total internal reflection.
The optical fiber has two layers, one is called core and the other is called cladding.
The refractive index of core is more than the cladding.
As a ray of light falls on the core at more than the critical angle for that pair of media(core and cladding), it suffers the total internal reflection at the interface.
V=IR
60-V
The current that passes through a 10-ohm resistor = I
I=60/10
6 amperes
Answer:
4.2s
Explanation:
Given parameters:
Power = 2190W
Mass of box = 1.47 x 10⁴g
distance = 6.34 x 10⁴mm
Unknown:
Time = ?
Solution:
Power is the rate at which work is done;
Mathematically;
Power = 
Time = 
Work done = weight x height
convert mass to kg;
100g = 1kg;
1.47 x 10⁴g = 14.7kg
convert the height to m;
1000mm = 1m
6.34 x 10⁴mm gives 63.4m
Work done = 14.7 x 9.8 x 63.4 = 9133.4J
Time taken = 
= 4.2s
The correct answer is A. Installation of rigid metal conduit requires grounding and the grounding equipment used may weaken the structure.
