which of the following is not a barrier to physical activity it is fear of injury I think.
Answer:
(a) The current should be in opposite direction
(b) The current needed is 39.8 A
Explanation:
Part (a)
Based, on right hand rule, the current should be in opposite direction
Part (b)
given;
strength of magnetic field, B = 370 µT
distance between the two parallel wires, d = 8.6 cm

At the center, the magnetic field strength is twice

R = d/2 = 8.6/2 = 4.3 cm = 0.043 m

Therefore, current needed is 39.8 A
Answer:
1.5F
Explanation:
Using
E= F/q
Where F= force
E= electric field
q=charge
F= Eq
So if qis tripled and E is halved we have
F= (E/2)3q
F= 1.5Eq=>> 1.5F
Electric field = potential difference
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distance between plates
Distance between plates = 45
----------
500
= 0.09 meters.