The correct answer is: <span>Unscrew one light, if the others remain on it is a parallel circuit.</span>
Answer:
Approximately 
.
Explanation:
The refractive index of the air 
is approximately 
.
Let 
denote the refractive index of the glass block, and let 
denote the angle of refraction in the glass. Let 
denote the angle at which the light enters the glass block from the air.
By Snell's Law:
.
Rearrange the Snell's Law equation to obtain:
.
Hence:
.
In other words, the angle of refraction in the glass would be approximately .
Answer:
Because the disturbances are in opposite directions for this superposition, the resulting amplitude is zero for pure destructive interference
Explanation:
Answer:
A.B = -38
Explanation:
A = 2i + 9j and B = -i - 4j.
So, A.B = (2i + 9j).(-i - 4j)
= 2i.(-i) + 2i.(-4j) + 9j.(-i) + 9j.(-4j)
= -2i.i - 8i.j - 9j.i - 36j.j
since i.i = 1, j.j = 1, i.j = 0 and j.i = 0, we have
A.B = -2(1) - 8(0) - 9(0) - 36(1)
A.B = -2 - 0 - 0 - 36
A.B = -38
