There is no current in the circuit shown in the figure below until the switch is closed. The current through the 20-? resistor the instant after the switch is closed is either [1] 15 A or [2] 5.0 A, and the current through the 20-? resistor after the switch has been closed a long time is either [3] 5.0 A or [4] 15 A. Which combination of the above choices is correct?





a.

[1] and [3]



b.

[1] and [4]



c.

[2] and [3]



d.

[2] and [4]



e.

None of these


d

Physics & Space Science

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