A40-turn, 4.0-cm-diameter coil with r=0.40ω surrounds a 3.0-cm-diameter solenoid. the solenoid is 20 cm long and has 200 turns. the 60 hz current through the solenoid is i=i0sin(2πft). what is the io if maximum induced current is .2 a?

Magnetic field B is produced when a current I Amphere passes through a solenoid. B is parallel to its axis.
B=U N/I I. N is number of turns in the solenoid of lm length
N=200, l= 20cm= 0.2m, I = 1₀sin (2πft) where  f is equal to 60Hz
B= 4π × 10⁻⁷(200/0.2) l₀ sin (2πft) T
=1.256 × 10⁻³ l₀ sin(2πft) Tesla
Area of the coil is πr² = π (1.5cm)² = 2.25π ×10⁴m²
magnetic flux which is through the coil is given by 
Ф = B.A = BA cosФ
ФФ = O since B is in direction of A
A= 40 ×π×2.25 ×⁻⁴m² which is the number of turns being 40.
Flux Ф through the coil is,
1.256 ×10⁻³ l₀ sin (2πft) ×9π ××10⁻³m²
=35.5 ×10⁻⁶ l₀ sin ₀(2πft)ab 
Ф is time-varying emf will be generated in the coil
∈= dФ/dt 
∈ = d/dt [35.5 × 10⁻d l₀ sin (2πft) ab]
∈ = 35.5 ×10⁻⁶ l₀ 2πf cos 2πftV
f = 60Hz
∈∈ 13376.4 ×10⁻⁶ l₀ cos 2πftV
Current I amp shall be induced in the cell of resistance Rohm so 
I= E/R
I = 13376.4 ×10⁻⁶ l₀ cos 2πft)V/0.4∩
=33441 ×10⁻⁶ I₀ cos 2πft A
I = 3344q × 10 ⁻⁶ l₀
But I = 0.2A
l₀ = (0.2)(10⁶)/33441 = 6.0A

Answer

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

explanation

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

The rearrangement of particles in a physical change. hope this