Answer:
z = 0.8 (approx)
Explanation:
given,
Amplitude of 1 GHz incident wave in air = 20 V/m
Water has,
μr = 1
at 1 GHz, r = 80 and σ = 1 S/m.
depth of water when amplitude is down to 1 μV/m
Intrinsic impedance of air = 120 π Ω
Intrinsic impedance of water = 
Using equation to solve the problem

E(z) is the amplitude under water at z depth
E_o is the amplitude of wave on the surface of water
z is the depth under water



now ,


taking ln both side
21.07 x z = 16.81
z = 0.797
z = 0.8 (approx)
Answer:
6
Explanation:
The magnetic field inside a solenoid is given by the following formula:

where,
B = Magnetic Field Inside Solenoid
μ₀ = permittivity of free space
n = No. of turns per unit length
I = Current Passing through Solenoid
For Solenoid 1:

For Solenoid 2:
n₂ = 6n₁
Therefore,

Diving equation 1 and equation 2:

Hence, the correct option is:
<u>6</u>
<h2>
Answer:7.14
,4.125
</h2>
Explanation:
Whenever an object is moving in a 2D frame,its motion can be analysed as if it is travelling in two independent 1D frames.
One of such independent 1D frames are along horizontal and another along vertical.
Let
be the total velocity.
Given that,
We call the horizontal velocity as
and the vertical velocity as
.
=

where
is the angle between the object and horizontal.
It is given that 


Answer is A of course lol Fire needs oxygen as an essential fuel to burn.