Answer:
The magnetic field strength needed is 1.619 T
Explanation:
Given;
Number of turns, N = 485-turn
Radius of coil, r = 0.130 m
time of revolution, t = 4.17 ms = 0.00417 s
average induced emf, V = 10,000 V.
Average induced emf is given as;
V = -ΔФ/Δt
where;
ΔФ is change in flux
Δt is change in time
ΔФ 
where;
N is the number of turns
B is the magnetic field strength
A is the area of the coil = πr²
θ is the angle of inclination of the coil and the magnetic field,
V = NBACos0/t
V = NBA/t
B = (Vt)/NA
B = (10,000 x 0.00417) / (485 x π x 0.13²)
B =1.619 T
Thus, the magnetic field strength needed is 1.619 T
Answer:
Voltage in the primary winding of the coil is 3.9 V
Explanation:
As we know by the principle of transformer we have
here we know that
now we have
Answer:
The work done by gravity is 784 J.
Explanation:
Given:
Mass of the block is, 
Height to which it is raised is, 
Acceleration due to gravity is, 
Now, work done by gravity is equal to the product of force of gravity and the distance moved in the direction of gravity. So,
Force of gravity is given as the product of mass and acceleration due to gravity.
. Now,
Therefore, the work done by gravity is 784 J.
Answer:
(a) 7.72×10⁵ J
(b) 4000 J
(c) 1.82×10⁻¹⁶ J
Explanation:
Kinetic Energy: This can be defined energy of a body due to its motion. The expression for kinetic energy is given as,
Ek = 1/2mv²................... Equation 1
Where Ek = Kinetic energy, m = mass, v = velocity
(a)
For a moving automobile,
Ek = 1/2mv².
Given: m = 2.0×10³ kg, v = 100 km/h = 100(1000/3600) m/s = 27.78 m/s
Substitute into equation 1
Ek = 1/2(2.0×10³)(27.78²)
Ek = 7.72×10⁵ J
(b)
For a sprinting runner,
Given: m = 80 kg, v = 10 m/s
Substitute into equation 1 above,
Ek = 1/2(80)(10²)
Ek = 40(100)
Ek = 4000 J
(c)
For a moving electron,
Given: m = 9.10×10⁻³¹ kg, v = 2.0×10⁷ m/s
Substitute into equation 1 above,
Ek = 1/2(9.10×10⁻³¹)(2.0×10⁷)²
Ek = 1.82×10⁻¹⁶ J
