The resistance of a wire is directly proportional to the length of the wire. That is the longer the length of the wire, the higher the resistance and the shorter the length of the wire, the smaller the resistance.
Answer:
13.78 mT
Explanation:
The peak voltage ε = ωNAB where ω = angular speed of coil = 1500 rpm = 1500 × 2π/60 rad/s = 50π rad/s = 157.08 rad/s, N = number of turns of coil = 250, A = area of coil = πr² where r = radius of coil = 10 cm = 0.10 m,
A = π(0.1 m)² = 0.03142 m² and B = magnetic field strength
So,
B = ε/ωNA
substituting the values of the variables into the equation given that ε = 17 V
So, B = ε/ωNA
B = 17 V/(157.08 rad/s × 250 turns × 0.03142 m²)
B = 17 V/(1233.8634 rad-turns-m²/s)
B = 0.01378 T
B = 13.78 mT
Given Information:
Current = I = 2.5 A
Magnetic field = B = 0.10 T
Radius = r = d/2 = 0.02/2 = 0.01 m
Length = L = 8 cm = 0.08 m
Required Information:
Number of turns = N = ?
Answer:
Number of turns = N ≈ 2547 turns
Step-by-step explanation:
The approximate model to find the number of turns is given by
B = μ₀nI
Where n = N/L
so
B = μ₀NI/L
N = BL/μ₀I
Where B is the magnetic field, L is the length of the solenoid, I is the current and μ₀ is the permeability of free space
N = (0.10*0.08)/(4πx10⁻⁷*2.5)
N ≈ 2547 Turns
