C is the first & the second question is A
Answer:
The average magnetic flux through each turn of the inner solenoid is 
Explanation:
Given that,
Number of turns = 22 turns
Number of turns another coil = 330 turns
Length of solenoid = 21.0 cm
Diameter = 2.30 cm
Current in inner solenoid = 0.140 A
Rate = 1800 A/s
Suppose For this time, calculate the average magnetic flux through each turn of the inner solenoid
We need to calculate the magnetic flux
Using formula of magnetic flux


Put the value into the formula


Hence, The average magnetic flux through each turn of the inner solenoid is 
When you rub a balloon on a sweater, for example, some electrons come off and end up on the balloon. The fibers have lost electrons giving them a positive charge. The rubber gained electrons giving it a negative charge. ... The positively charged fibers are now attracted to the negatively charged balloon.
Answer:
1.15 m/s
Explanation:
Part of the question is missing. Found the missing part on google:
"1. A hanging mass of 1500 grams compresses a spring 2.0 cm. Find the spring constant in N/m."
Solution:
First of all, we need to find the spring constant. We can use Hooke's law:

where
is the force applied to the spring (the weight of the hanging mass)
x = 2.0 cm = 0.02 m is the compression of the spring
Solving for k, we find the spring constant:

In the second part of the problem, the spring is compressed by
x = 3.0 cm = 0.03 m
So the elastic potential energy of the spring is

This energy is entirely converted into kinetic energy of the cart, which is:

where
m = 500 g = 0.5 kg is the mass of the cart
v is its speed
Solving for v,
