Page 711 - SUBSEC October 2017

Page 711 - SUBSEC October 2017_Neat

P. 711

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(c) In the space below, sketch the graph of the voltage across the capacitor versus time,
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from the time the switch reaches P until the capacitor fully charges.

[3 marks]

(d) The switch is now moved to position Q and the capacitor discharges.

(i) In the space below, sketch the graph of the voltage across the capacitor, Vc,
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versus time, from the time the switch reaches Q until the capacitor
discharges.

[3 marks]

(ii) Write the equation for the current during capacitor discharge.

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[1 mark]

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(iii) The initial current Io was 100 mA. R is 47 KΩ and C is 1 000 µF. Determine the
time constant of the discharge in seconds.

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[3 marks]

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