A laboratory bench setup includes two identical dry cells connected in series to form…
PHYSICS · Multi-part · AP · Physics 2: Algebra-based · Electric Circuits · Electric Circuits
Problem
A laboratory bench setup includes two identical 1.5V dry cells connected in series to form a 3.0V source. The positive terminal of this source is connected to node A. From A, three separate conductive paths reach node B:
1. Path I passes through a light–emitting diode (LED) that requires a minimum forward potential difference of 2.0V to emit light.
2. Path II passes through a resistor R=50Ω.
3. Path III is a short jumper wire of negligible resistance.
Node B is connected directly to the negative terminal of the 3.0V source. Assume all connecting wires are ideal.
(a) Classify the overall electrical state of the circuit and justify your classification based on potential differences along the three paths.
(b) Will the LED emit light under these conditions? Explain quantitatively or qualitatively as appropriate.
(c) Calculate the total current supplied by the battery pack.
(d) In an attempt to troubleshoot, the jumper wire of Path III is removed while leaving the rest of the circuit intact. Describe how the circuit state, LED behavior, and battery current change when the jumper is absent compared with parts (a)–(c).