Answer:
33,458.71 turns
Explanation:
Given: L = 37 cm = 0.37 m, B= 0.50 T, I = 4.4 A, n= number of turn per meter
μ₀ = Permeability of free space = 4 π × 10 ⁻⁷
Solution:
We have B = μ₀ × n × I
⇒ n = B/ (μ₀ × I)
n = 0.50 T / ( 4 π × 10 ⁻⁷ × 4.4 A)
n = 90,428.94 turn/m
No. of turn through 0.37 m long solenoid = 90,428.94 turn/m × 0.37
= 33,458.71 turns
Ammonia because it doesn't have nitrogen
Answer:

Explanation:
We are given that
Diameter of wire=d=4.12 mm
Radius of wire=r

Current=I=8 A
Drift velocity=
We have to find the density of free electrons in the metal
We know that
Density of electron=
Using the formula
Density of free electrons=
By using Area of wire=

Density of free electrons=
Answer:
From ohms law,
V=IR
R=V/I =12.0/150 =0.08 ohm.
Answer:
Explanation:
In the first case you can use the expression for the Doppler effect when the source is getting closer and getting away
( 1 )
( 2 )
f' = perceived frequency when the source is getting closer
f'' = perceived frequency when the source is getting away
f = source frequency
v = relative speed
vs = sound speed
by dividing (1) and (2) you have

but this is the relative velocity, you have that

a. hence, the speed of the police car is 102.5m/s