C) it decreased
because atmospheric pressure decreases as we move up.
Two examples of where you can find permanent magnets are
1.compass
2.speakers
Answer:
a) 
b) 
Explanation:
Given data:
Electric field = 1.47 N/C
velocity of electron is 
distance of point b from point A is 0.55 m
we know that acceleration of particle is given as
a) for electron



from equation of motion we have



b) for proton


from equation of motion we have



Answer
given,
Side of copper plate, L = 55 cm
Electric field, E = 82 kN/C
a) Charge density,σ = ?
using expression of charge density
σ = E x ε₀
ε₀ is Permittivity of free space = 8.85 x 10⁻¹² C²/Nm²
now,
σ = 82 x 10³ x 8.85 x 10⁻¹²
σ = 725.7 x 10⁻⁹ C/m²
σ = 725.7 nC/m²
change density on the plates are 725.7 nC/m² and -725.7 nC/m²
b) Total change on each faces
Q = σ A
Q = 725.7 x 10⁻⁹ x 0.55²
Q = 219.52 nC
Hence, charges on the faces of the plate are 219.52 nC and -219.52 nC