Answer:
(a) ΔФ = -0.109W
(b) emf = 28.43V
(c) Iin = emf/R
Explanation:
(a) In order to calculate the magnetic flux you use the following formula:
(1)
B: magnitude of the magnetic field = 1.40T
A: area of the rectangular coil = (0.23m)(0.34m)=0.078m^2
Where it has been taken into account that at the beginning the normal vector to the cross sectional area of the coil, and the magnetic field vector are parallel. When the coil is rotated the vectors are perpendicular.
Then, you obtain:

The change in the magnetic flux is -0.109 W
(b) During the rotation of the coil the emf induced is given by:
(2)
N: turns of the coil = 60
ΔФ: change in the magnetic flux = 0.109W
Δt: lapse time of the rotation = 0.230s
You replace the values of the parameters in the equation (2):

The induced emf is 28.43V
(c) The induced current in the coil is given by:
(3)
R: resistance of the coil (it is necessary to have this value)
emf :induced emf = 28.43V
Basically velocity is a vector quantity and is specified in m/s (meters/second). Speed is the distance traveled by an object where as, velocity is distance traveled by an object per unit time in a particular direction. Speed is a scalar quantity where as velocity is a vector quantity
When light passes from a faster medium into a slower medium, light will be refracted toward a line drawn perpendicular to the point of refraction. <em>(B)</em>
Answer:
Rotational inertia of the object is, 
Explanation:
Given that,
Mass of the object, m = 20 kg
Torsion constant of the wire, K = 0.85 N-m
Number of cycles, n = 69
Time, t = 66 s
To find,
The rotational inertia of the object.
Solution,
There exists a relationship between the moment of inertia, time period and the torsion constant of the spring is given by :

Here I is the moment of inertia
T is the time period, and it is equal to the number of cycles per unit time



So, the rotational inertia of the object is
.
length × width × height
20 cm × 10 cm × 5 cm = 1,000 cm