Two Parallel Circular Plates, Each with a Radius Of $7.0 \mathrm {~mm}$

question 50

Multiple Choice

Two parallel circular plates, each with a radius of $7.0 \mathrm {~mm}$ and carrying equal-magnitude surface charge densities of $\pm 3.0 \mu \mathrm { C } / \mathrm { m } ^ { 2 }$ , are separated by a distance of $1.0 \mathrm {~mm}$ with only air between them. How much energy is stored in these plates? $\left( \varepsilon _ { 0 } = 8.85 \times 10 ^ { - 12 } \mathrm { C } ^ { 2 } / \mathrm { N } \cdot \mathrm { m } ^ { 2 } \right)$

• A) \(250 \mathrm {~nJ}\)
• B) \(25 \mathrm {~nJ}\)
• C) \(78 \mathrm {~nJ}\)
• D) \(7.9 \mathrm {~nJ}\)

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Definitions:

Thresholds

Points or levels at which something starts or changes, often used in context with physiological or psychological responses.

Sensitivity Effects

The impacts on outcomes in a study due to variations in how sensitive measurements or instruments are to changes in the independent variable.

Signal-Detection Terms

Terms used in signal detection theory, a means to quantify the ability to discern between information-bearing patterns (signals) and random patterns that distract from the information (noise), in various fields like psychology and telecommunications.

Candidate

An individual who is being considered for a position, status, or undertaking, often in the context of elections or selection processes.