Two flat 4.0 cm × 4.0 cm electrodes carrying equal but opposite charges are spaced 2.0 mm apart with their midpoints opposite each other.Between the electrodes but not near their edges,the electric field strength is 2.5 × 10⁶ N/C.What is the magnitude of the charge on each electrode?

Question

Quizplus · Accepted Answer

The electric field strength between two parallel plates with equal but opposite charges on each plate is given by:

E = σ/ε0

where σ is the surface charge density and ε0 is the permittivity of free space.

Since the plates are flat and the electric field is uniform between them, we can assume that the charge is uniformly distributed on each plate. Therefore, the surface charge density is given by:

σ = Q/A

where Q is the charge on each plate and A is the area of each plate.

The electric field strength is given as E = 2.5 × 10^16 N/C. Plugging in the given values, we get:

2.5 × 10^16 N/C = Q/(ε0 × 4.0 cm × 2.0 mm)

Solving for Q, we get:

Q = 35 nC

Therefore, each electrode carries a charge of 35 nC, or choice A.

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