Answer:
iv) It is 9x bigger than before
Explanation:
As the amplitudes of the new speakers add directly with the original one, taking into account the phase that they have, the composed amplitude of the sound wave is as follows:
At = A + 4A -2A = 3 A
The intensity of the wave, assuming it propagates evenly in all directions, is constant at a given distance from the source, and can be expressed as follows:
I = P/A
where P= Power of the wave source, A= Area (for a point source, is equal to the surface area of a sphere of radius r, where is r is the distance to the source along a straight line)
For a sinusoidal wave, the power is proportional to the square of the amplitude, so the intensity is proportional to the square of the amplitude also.
If the amplitude changes increasing three times, the change in intensity will be proportional to the square of the change in amplitude, i.e., it will be 9 times bigger.
So, the statement iv) is the right one.
In our Solar System, Jupiter is the largest planet we have. it has the surface area of 23.71 billion mi^2. it beats all the other planets in both mass and volume.
Answer:
The electric field is 
Explanation:
Given that,
Radius = 2.00 cm
Number of turns per unit length 
Current 
We need to calculate the induced emf

Where, n = number of turns per unit length
A = area of cross section
=rate of current
Formula of electric field is defined as,

Where, r = radius
Put the value of emf in equation (I)
....(II)
We need to calculate the rate of current
....(III)
On differentiating equation (III)

Now, put the value of rate of current in equation (II)


Hence, The electric field is 