Complete question is;
The energy flow to the earth from sunlight is about 1.4kW/m²
(a) Find the maximum values of the electric and magnetic fields for a sinusoidal wave of this intensity.
(b) The distance from the earth to the sun is about 1.5 × 10^(11) m. Find the total power radiated by the sun.
Answer:
A) E_max ≈ 1026 V/m
B_max = 3.46 × 10^(-6) T
B) P = 3.95 × 10^(26) W
Explanation:
We are given;
Intensity; I = 1.4kW/m² = 1400 W/m²
Formula for maximum value of electric field in relation to intensity is given as;
E_max = √(2I/(ε_o•c))
Where;
ε_o is electric constant = 8.85 × 10^(-12) C²/N.m²
c is speed of light = 3 × 10^(8) m/s
Thus;
E_max = √(2 × 1400)/(8.85 × 10^(-12) × 3 × 10^(8)))
E_max ≈ 1026 V/m
Formula for maximum magnetic field is;
B_max = E_max/c
B_max = 1026/(3 × 10^(8))
B_max = 3.46 × 10^(-6) T
Formula for the total power is;
P = IA
Where;
A is area = 4πr²
We are given;
Radius; r = 1.5 × 10^(11) m
A = 4π × (1.5 × 10^(11))² = 2.82 × 10^(23) m²
P = 1400 × 2.82 × 10^(23)
P = 3.95 × 10^(26) W
The statement that best describes an external circuit is "<span>D. The flow of an alternating current switches direction when a generator's terminals change its charge." The main difference between direct and alternating current is the direction of flow. Direct current follows only one direction from negatve to positive, while alternating current changes direction periodically.</span>
Answer:
0.32 V
Explanation:
N = 10, A = 0.23 m^2, B = 0.47 T, t = 0.34 s
The average induced emf is given by
e = - N dФ / dt
Where, dФ be the change in magnetic flux in time dt.
dФ / dt = d / dt (B A) = A dB/dt
So,
e = - 10 x 0.23 x 0.047 / 0.34 = - 0.32 V
The negative sign shows the direction of induced emf.
They are the very bases of life, no life would exist without cells
Unable to be noticed or not felt because of feeling slight
