Answer:
it is sooo easy u need to use magnetic panels on the rail and put the magnet on the train it works under the principal of magnetic
Answer:
Ratio of magnetic field will be 
Explanation:
We have given radius of the loop r = 30 mm = 0.03 m
We know that magnetic field at the center of the loop is given by
---------eqn 1
Number of turns in the solenoid is given as n = 3 turn per mm = 3000 turn per meter
We know that magnetic field due to solenoid is given by
-------------eqn 2
Now dividing eqn 1 by eqn 2

Answer:
1) the capacitance of the capacitor increases. This is due to the induction of opposite charges on the two surfaces of the dielectric by the plate, this increased the charge in the field, from C =Q/v, it is seen that capacitance C will increase with increase in Q since v is constant.
2) the electric field intensity will also increase with increase in electric charges provided plate separation d remains constant.