Here is your answer:
1. A alternating current is a current "is an electric current which periodically reverses direction." A direct current is a "<span>current which flows only in one direction."
2. They are alike because both are "they both are able to travel in different directions." How they are not alike is that a "alternating current travels in a reverse direction but a direct current can only travel in one direction each current."
Hope this helps!</span>
Answer:
Pushing molecules like a wave.
Explanation:
Answer:
Liquid's index of refraction, n₁ = 1.27
Explanation:
It is given that,
The critical angle for a liquid in air is, 
We have to find the refractive index of the liquid. Critical angle of a liquid is defined as the angle of incidence in denser medium for which the angle of refraction is 90°.
Using Snell's law as :
Here, 
Where
n₂ = Refractive index of air = 1
n₁ = refractive index of liquid
So,
n₁ = 1.269
or n₁ = 1.27
Hence, the refractive index of liquid is 1.27
Answer:
decrease
Explanation:
Addition of a lubricant such as oil to a surface will decrease friction. This makes the surface more greasy or slippery. This is very much efficient in machines, for example.
Answer:
162 KJ
Explanation:
The electrical energy can be calculated using the formula
E = V×I×t
Where, V= voltage = 120 V
I is current in ampere = 7.5 A and t is time in seconds
1 hour = 3600 sec
Therefore, 0.05 hour = 3600×0.05 = 180 sec
Substitute the values in above equation find electrical power
E = 120×7.5×180
= 162000 J
= 162 KJ
Therefore, the electrical energy use of the microwave = 162 KJ
