Answer:
Reflective
Explanation:
The radiation pressure of the wave that totally absorbed is given by;
and While the radiation pressure of the wave totally reflected is given by;
Now compare the two-equation you can clearly see that the pressure due to reflection is larger than absorption therefore the sail should be reflective.
Answer:
A
Explanation:
E. An ocean wave moving through water is an example of a mechanical wave
e.g sound waves wave on a rope or string
and Ans a is also correct
Answer:
Explanation:
i )
When it is disconnected with the battery , the charge stored in it becomes fixed . When the plate distance becomes half , its capacitance becomes twice from C to 2C . Let charge stored in it at the time of disconnection from battery be Q . Let plate separation reduces from d to d / 2
So charged stored in it will remain unchanged .
ii )
Potential difference = charge / capacitance
in the first case potential difference = Q / C
in the second case potential difference = Q / 2C
So potential difference becomes half .
iii ) electric field = potential diff / plate separation
in the first case electric field = Q / (d x C )
in the second case electric field = 2 Q / (d x 2C)
= Q / (d x C )
So electric field remains unchanged .
iv)
energy stored in first case = Q² / 2C
In the second case energy stored = Q² / 2x2C
so energy stored becomes half .
Magnetic force obeys an inverse square law with distance. ... If the distance between two magnets is halved the magnetic force between them will increase to four times the initial value.
