Answer:
a) 
b)
parallel to the earth surface.
- In this case according to the Fleming's left hand rule the direction of movement of bee must be in a direction parallel to the earth surface and perpendicular to the electric field at the same time.
Explanation:
Given:
mass of the bee, 
charge acquired by the bee, 
a.
Electrical field near the earth surface, 
Now the electric force on the bee:
we know:




The weight of the bee:



Therefore the ratio :


b.
The condition for the bee to hang is its weight must get balanced by the electric force acing equally in the opposite direction.
So,



parallel to the earth surface.
- In this case according to the Fleming's left hand rule the direction of movement of bee must be in a direction parallel to the earth surface and perpendicular to the electric field at the same time.
The Doppler effect occurs when a source of sound or light
moves either toward or away from the observer.
Answer:

Explanation:
Given that
Radius of track = R
Radius of ball = r
The ball can be treated as solid sphere, so
The moment of inertia of ball

When the ball reach at the lowest position then it will have both angular and linear speed.
Condition for rolling without slipping v= ωr
Form energy conservation

v= ωr





