Answer:
Explanation:
Number of turns
N = 210turns
Length of solenoid
l = 0.18m
Cross sectional area
A = 4cm² = 4 × 10^-4m²
A. Inductance L?
Inductance can be determined using
L = N²μA/l
Where
μ is a constant of permeability of the core
μ = 4π × 10^-7 Tm/A
A is cross sectional area
l is length of coil
L is inductance
Therefore
L = N²μA / l
L=210² × 4π × 10^-7 × 4 × 10^-4 / 0.18
L = 1.23 × 10^-4 H
L = 0.123 mH
B. Self induce EMF ε?
EMF is given as
ε = -Ldi/dt
Since rate of decrease of current is 120 A/s
Then, di/dt = —120A/s, since the current is decreasing
Then,
ε = -Ldi/dt
ε = - 1.23 × 10^-4 × -120
ε = 0.01478 V
ε ≈ 0.015 V
B. Physical Change - T<span>he molecules do not change shape or size. They do not contract or expand only.</span>
Answer:
It formed from the same cloud of dust that our entire galaxy is made from
Answer:
A. 36,000 W
Explanation:
= mass of the car = 900 kg
= Initial speed of the car = 20 m/s
= Final speed of the car = 0 m/s
= Work done by the brakes on the car
Magnitude of work done on the car by the brakes is same as the change in kinetic energy of the car.hence

= time taken by the car to come to stop = 5 s
= Average power produced by the car
Average power produced by the car is given as

Answer
A compound is made of atoms of more than one or two different elements. Sorry, I really don't have an explanation as I'm not a scientist. Sorry.