Answer:
The value is 
Explanation:
From the question we are told that
The diameter of the ring is 
The length of the solenoid is 
The diameter of the solenoid is 
The number of turns is N = 1500
The change in current in the solenoid is 
The time taken is 
Generally the radius of the ring is

=> 
=> 
Generally the area of the ring is mathematically represented as

=>
=> 
Generally the induced emf is mathematically represented as

Here

Here
is the permeability of free space with value

So

=> 
So

=> 
Answer:
<em>The new force is 2/3 of the original force</em>
Explanation:
<u>Coulomb's Law
</u>
The electrical force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between the two objects.
Written as a formula:

Where:

q1, q2 = the objects' charge
d= The distance between the objects
Suppose the first charge is doubled (2q1) and the second charge is one-third of the original charge (q2/3). Now the force is:

Factoring out 2/3:

Substituting the original force:

The new force is 2/3 of the original force
Answer:
momentum=mass×velocity
momentum =400kg×20m/s=8000kg.m/s
Answer:
option C
Explanation:
given,
force act on west = 20 lb
force act at 45° east of north = 80 lb
magnitude of force = ?
∑ F y = 80 cos 45⁰
F y = 56.57 lb
magnitude of forces in x- direction
∑ F x = -20 + 80 sin 45⁰
= 36.57 lb
net force
F = 
F = 
F = 67.36 lb≅ 67 lb
hence, the correct answer is option C