The AU ... Astronomical Unit ... used to be defined as the average distance between the Sun and Earth during the year.
Now it's defined as 149,597,870,700 meters exactly.
Answer:
A) μ = A.m²
B) z = 0.46m
Explanation:
A) Magnetic dipole moment of a coil is given by; μ = NIA
Where;
N is number of turns of coil
I is current in wire
A is area
We are given
N = 300 turns; I = 4A ; d =5cm = 0.05m
Area = πd²/4 = π(0.05)²/4 = 0.001963
So,
μ = 300 x 4 x 0.001963 = 2.36 A.m².
B) The magnetic field at a distance z along the coils perpendicular central axis is parallel to the axis and is given by;
B = (μ_o•μ)/(2π•z³)
Let's make z the subject ;
z = [(μ_o•μ)/(2π•B)] ^(⅓)
Where u_o is vacuum permiability with a value of 4π x 10^(-7) H
Also, B = 5 mT = 5 x 10^(-6) T
Thus,
z = [ (4π x 10^(-7)•2.36)/(2π•5 x 10^(-6))]^(⅓)
Solving this gives; z = 0.46m =
<h2>Ratio of final kinetic energy to initial kinetic energy is 16.</h2>
Explanation:
Kinetic energy , KE = 0.5mv²
Here car speeds up to four times the initial speed, we need to find ratio of final kinetic energy to initial kinetic energy.
Final speed = 4 x Initial speed = 4v
Initial KE = 0.5mv²
Final KE = 0.5 x m x (4v)²
Final KE = 16 x 0.5 x m x v²
Final KE = 16 x Initial KE
Ratio of final kinetic energy to initial kinetic energy is 16.
A simple electromagnet consisting of a coil of insulated wire wrapped around an iron core<span>. A </span>core<span> of ferromagnetic material like </span>iron<span> serves to increase the magnetic field created. The strength of magnetic field </span>generated<span> is proportional to the amount of </span>current<span> through the winding.</span>