Answer:
A
Explanation:
From a Solenoid we know that a magnetic fiel is always inversely proportional to lenght L or BL = constant

As I is constant



A closed circle means the number is included and an open circle means its not.
Answer:
No
Explanation:
Displacement is how far between your initial and finishing position.
If one lap around the track is 400 m and the sprinter ran 1 lap around the track. Then the sprinter's distance is 400 m and their displacement is 0 m
If the sprinter ran 400 m in a straight line however, then it would be equal.
But since the sprinter ran 1 lap around there is no displacement.
I hope this helped you...
Answer:

Explanation:
We can assume this problem as two concentric spherical metals with opposite charges.
We have also to take into account the formulas for the electric field and the capacitance. Hence we have

Where k is the Coulomb's constant. Furthermore, by taking into account the expression for the potential and by integrating
![dV=Edr\\\\V=\int_{R_1}^{R_2}Edr=-\int_{R_1}^{R_2}\frac{kQ}{r^2}dr\\\\V=kQ[\frac{1}{R_2}-\frac{1}{R_1}]](https://tex.z-dn.net/?f=dV%3DEdr%5C%5C%5C%5CV%3D%5Cint_%7BR_1%7D%5E%7BR_2%7DEdr%3D-%5Cint_%7BR_1%7D%5E%7BR_2%7D%5Cfrac%7BkQ%7D%7Br%5E2%7Ddr%5C%5C%5C%5CV%3DkQ%5B%5Cfrac%7B1%7D%7BR_2%7D-%5Cfrac%7B1%7D%7BR_1%7D%5D)
Hence, the capacitance is
![C=\frac{1}{k[\frac{1}{R_2}-\frac{1}{R_1}]}](https://tex.z-dn.net/?f=C%3D%5Cfrac%7B1%7D%7Bk%5B%5Cfrac%7B1%7D%7BR_2%7D-%5Cfrac%7B1%7D%7BR_1%7D%5D%7D)
but R1=a and R2=b

HOPE THIS HELPS!!
Answer:
Explanation:
v = 50 km / h
= 13.89 m /s
When a vehicle runs on a circular path , it is static friction which prevents it from getting overturned .
static friction = μs mg
centripetal force = m v² / R
m v² / R = μs mg
R = v² / μs x g
= 13.89² / .7 x 9.8
= 28.12 m .