Answer:
It helps us to know or be aware of some things that happen regular and teaches us about laws that guide us
Answer:
Number of turns per unit length will be 
Explanation:
We have given that strength of the magnetic field produced by the solenoid B = 7 T
Current in the solenoid i = 200 A
Let the number of turns per unit length is n
Magnetic field due to solenoid is given as
here
is permeability of free space n is number of turns per unit length and i is current
So 

c.The warm surface water results in moist air and more rainfall.
Explanation:
- During upwelling, cold water in the ocean is stirred up and brought to the surface.
- The warmer surface water is then taken into deeper parts of the ocean.
- Upwelling allows for nutrient mixing in the ocean and allows for useful gases to circulate well.
- The warm surface water causes the air to be moisty.
- When the air is carried landward towards the coast, it leads to rainfall when the saturated air releases the water.
- The air then becomes cold and dry and it rises up.
- Therefore, warm surface water results in moist air and more rainfall.
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Ocean current brainly.com/question/4117397
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Answer:
* in a tube with both ends open
λ = 2L / n n = 1, 2, 3,…
* tube with one end open and the other closed.
λ = 4L / n n = (2n ’+ 1 )
Explanation:
When a sound wave enters a pipe, a resonance process occurs, whereby only some wavelengths can occur.
* in a tube with both ends open
in this case there are maximums at each end, so if the length of the had is L
λ = 2L 1st harmonic
λ = 2 L / 2 2nd harmonic
λ = 2L / 3
λ = 2L / n n = 1, 2, 3,…
* In the case of a tube with one end open and the other closed.
At the open end there is a belly and at the closed end a node
λ = 4L 1st harmonic
λ = 4L / 3 3rd harmonic
λ = 4L / 5
λ = 4L / n n = 1, 3, 5,… odd
n = (2n ’+ 1 ) where n’ are all integers