Answer:
The time rate of change of flux is

Explanation:
Given :
Current
A
Area of plate

Plate separation
m
(A)
First find the capacitance of capacitor,

Where 

F
But 
Where 


Now differentiate above equation wrt. time,



Therefore, the time rate of change of flux is

Answer:
If the system consists of the block only, the work done by the gravity is negative.
If the system consists of the block and the earth the work done by the gravity is zero.
Explanation:
If the system consists of the block only, then the system experiences two external forces: one exerted by the hand that lifts the block vertically upward and other exerted by the earth (gravity), which is opposed to the movement of the system, so the work done by gravity is negative.
On the other hand, if the system consists of the block and the earth, then only exists a external force which is the exerted by the hand. So, the force exerted by gravity is zero.
Answer:
I would say the answer is A... but I'm not so sure ....
When a pendulum is at the midpoint of its oscillation, hanging straight down ...
-- that's the fastest it's going to swing, so its kinetic energy is maximum;
and
-- that's the lowest it's going to get, so its potential energy is minimum.
'c' is your choice.