Answer:
Either heat added or mechanical work done.
Explanation:
Since he found stirring rod on the desk and a cigarette lighter. This means that the beaker was probably either heated with the aid of fire from the lighter.
Also, the stirring rod could have been used to stir the water which will increase the kinetic energy which also means an increase in temperature.
Thus, it's either heat was added or mechanical work was done as a result of stirring. 
 
        
             
        
        
        
Answer:
Part A:

Part B:
Option B (Towards the South)
Explanation:
Part A:
Magnitude if electric field E:
E=Force/charge
Force=2.04×10−14 N
Charge=1.6×10−19 C

Part B:
Option B (Towards the South)
As electron is experiencing the force towards south,it means the direction of the electric field is towards the south because direction of field lines is from positive to negative, so proton is moving towards south it means negative charge is in south to which proton is attracted. So electric field is towards South.
 
        
             
        
        
        
Theyre all in constant motion