Two light waves will interfere constructively if the path-length difference between them is a whole number.
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SUPERPOSITION</h3>
The principle of superposition state that, when two or more waves meet at a point, the resultant displacement at that point is equal to the sum of the displacements of the individual waves at that point.
Interference of waves can either be constructive, or destructive.
The two light waves, initially emitted in phase, will interfere constructively with maximum amplitude if the path-length difference between them is a whole number of wavelenght 1λ, 2λ, 3λ, 4λ etc
The equivalent phase differences between the waves will be 2
or 360 degrees, 4
or 720 degrees, 6
1080 degrees etc
Therefore, the two light waves, initially emitted in phase, will interfere constructively with maximum amplitude if the path-length difference between them is a whole number.
Learn more about Interference here: brainly.com/question/25310724
Answer:
(a) 
(b) 
Explanation:
(a) The surface current density of a conductor is the current flowing per unit length of the conductor.

Considering a wire, the current is uniformly distributed over the circumferenece of the wire.

The radius of the wire = a

The surface current density 
(b) The current density is inversely proportional
......(1)
k is the constant of proportionality

........(2)
substituting (1) into (2)





substitute 

Answer:
C. you're able to reverse out of the parking spot
Explanation:
Straight-in parking is an approach of parking that allows a more flexible traffic layout where a driver can approach the spot from either direction and still safely park within the lines. It thus helps to prevent blockage of cars. Each car can move in and out freely preventing it from congestion.
This way of parking can leave you safe when you able to reverse out of the parking spot. It gives you greater control and makes it easier to maneuver out space. The benefits of Straight-in parking are,
- Allows for two-way traffic
- Drivers can line up the vehicle from multiple angles
- Saves time for drivers
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