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RC CIRCurrs Name The circuit at right contains a battery, a bulb, a switch EM HW

ID: 1773620 • Letter: R

Question

RC CIRCurrs Name The circuit at right contains a battery, a bulb, a switch EM HW-101 1. and a capacitor. The capacitor is initally uncharged Describe the behavior of the bulb in the two situations below a. Bulb A The switch is first moved to position 1 Describe the behavior of the bulb from just after the switch is closed until a long time later. Explain. i· Capacitor ii. The switch is now moved to position 2. Describe the behavior of the bulb from just after the switch is closed until a long time later. Explain your reasoning. A second identical bulb is now added to the circuit as shown. The capacitor is discharged. b. Bulb B The switch is now moved to position 1. Describe the behavior of bulbs B and C from just after the switch is closed until a long time i· Bulb C Battery- later. Explain. How does the initial brightness of bulb C compare to the initial brightness of bulb A in question i of part a? Explain your reasoning. A long time after the switch is closed, is the potential difference across the capacitor greater than, less than, or equal to the potential difference across the battery? Explain

Explanation / Answer

1a) i)This is charging of a capacitor case. The current decays with time. The bulb glows bright initially, but then goes dimmer with time, and after a long time it stops glowing.

ii)This is discharging of capacitor case. The current decays with time as the capacior get discharged. So bulb glows bright initially, but then goes dimmer with time, and after a long time it stops glowing.

b)i) Just like (a-i) this is charging.  The current decays with time. The bulbs glow bright initially, but then go dimmer with time, and after a long time they stop glowing.

Initial brightness of this case is less than a-i because initial current is less because of presence of two resistors.

After a long time POTENTIAL DIFFERENCE across capacitor is equal to that across battery.

b-ii) This is discharging of capacitor case. The current decays with time as the capacior get discharged. So bulbs glow bright initially, but then goes dimmer with time, and after a long time they stop glowing.

Initial brightness is less because of increased resistance, leading to less current.

Potential difference across capacitor is less tha that across battery as after it is fully discharged it has zero potential difference.