A Proton Beam That Carries a Total Current of 1

question 17

Multiple Choice

A proton beam that carries a total current of 1.3 mA has 10.0 mm diameter. The current density in the proton beam increases linearly with distance from the center. This is expressed mathematically as J(r) = J₀ (r/R) , where R is the radius of the beam and J₀ is the current density at the edge. Determine the value of J₀.

• A) 25 A/m²
• B) 6.2 A/m²
• C) 12 A/m²
• D) 17 A/m²

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Definitions:

Efficient

The most efficient employment of resources to attain the intended result while minimizing waste or exertion.

Better Off

A situation where an individual or group is in a more favorable or advantageous position than before.

Economic Efficiency

A condition in which all available resources are utilized in a way that produces the highest combination of quantity and quality of goods and services.

Market Economy

An economic system in which decisions on production and consumption are based on voluntary exchange in markets.