The magnetic field strength in a coil is directly proportional to the number of turns, or loops, in the coil.
Therefore, when there are four loops instead of one, the magnetic field strength has increased four times, making it harder to push the magnet in.
Answer: Resistance = 
The approximate diameter of a penny is, <em>d</em> = 20 mm
thickness of penny is, <em>L = </em> 1.5×
mm
The area of penny along circular face is,
= 3.14×
m²
The resistivity of copper is <em>ρ</em> = 1.72 x 10-8 Ωm.
Resistance,
Answer:
A. 5.4 * 10^(-4) m
B. 500V
Explanation:
A. Electric potential, V is given as:
V = kq/r
This means that radius, r is
r = kq/V
r = (9 * 10^9 * 30 * 10^(-12))/500
r = (270 * 10^(-3))/500
r = 5.4 * 10^(-4) m
B. Now the radius is doubled and the charge is doubled,
V = (9 * 10^9 * 2 * 30 * 10^(-12))/(2 * 5.4 * 10^(-4) * 2)
V = 500V
Weight expressed in Newtons is expressed in the equation whereby Weight= the mass of an object * the force of gravity. The force of gravity on earth is a constant 9.8 meters per second squared. Therefore if weight (w) = 63 N and the force of gravity is 63 N then the mass must equal 6.43 kg. Because the equation for weight is w=mg so 63 N (w) = m * 9.8 m/s^2.
