Answer:
The magnitude of the force, B = 5 Tesla, Up (North) direction
Explanation:
Magnetic force F= Eq where Electric field, E = 750 NC
and charge, q = -70 μC = -7 × C
C
F = 750 ×  -7 ×
F = 0.0525
But F = qvB; B = 
where B is the magnetic field
= 0.0525 ÷ ( -7 × × 30)
 × 30)
B = 5.0 Teslas
The force on a negative charge is in exactly the opposite direction to that on a positive charge. 
Hence the direction of the charge is up (North).
 
        
                    
             
        
        
        
Answer:
This difference is kept to a minimum because the resistance in transformers is a few tens of ohms and the resistance of modern voltmeters is of the order of MΩ.
Explanation:
A voltmeter is built by a galvanometer and a resistance in series, this set is connected in parallel to the resistance where the voltage is to be measured, therefore the voltage is divided between the voltmeter and the element to be measured, consequently the measured voltage It is less than the calculated one, since for them the resistance of the voltmeter is assumed infinite.
This difference is kept to a minimum because the resistance in transformers is a few tens of ohms and the resistance of modern voltmeters is of the order of MΩ.
 
        
             
        
        
        
Answer:
b
Explanation:
 i took the quiz i think its right
 
        
             
        
        
        
Mass and distance
force /pull of gravity decreases with the increase in separation between the two bodies
the amount of gravity an object possesses is proportional to the mass of that object.
        
             
        
        
        
I beleive she isnt doing any work due to holding the box motionless, you must be exerting a force in the direction of the box motion. If she is just standing there holding the box their isn't no work becuase no distance has been covered. work = force = distance.