A student performs two experiments.
In the first experiment, they apply a square wave voltage signal to a simple series RC circuit . They then measure the voltage across the resistor ( ) and the capacitor ( ) on an oscilloscope and look at the measured waveforms.
In the second experiment, they apply a square wave voltage signal to a simple series RL circuit . They then measure the voltage across the resistor ( ) and the inductor ( ) on an oscilloscope and look at the measured waveforms.
In both experiments, they notice some “spiky” behaviour. Which of the following statements most accurately describes the spiky behaviour?

Question

A student performs two experiments. 
 In the first experiment, they apply a  square wave  voltage signal to a simple  series RC circuit . They then measure the voltage across the  resistor  (  ) and the  capacitor  (  ) on an oscilloscope and look at the measured waveforms. 
 In the second experiment, they apply a  square wave  voltage signal to a simple  series RL circuit . They then measure the voltage across the  resistor  (  ) and the  inductor  (  ) on an oscilloscope and look at the measured waveforms. 
 In both experiments, they notice some “spiky” behaviour. Which of the following statements  most accurately describes  the spiky behaviour?

Accepted Answer

In the RC circuit,    will spike, and in the RL circuit,    will spike. This is because    must be continuous, and    must be continuous, forcing the other component in each circuit to absorb the instantaneous input change (via KVL).

Answer

In both circuits,    will spike. In the RC circuit, this is because    cannot change instantly, and in the RL circuit, this is because    cannot change instantly.

Answer

In the RC circuit, both    and    will spike. In the RL circuit, both    and    will spike. This is likely due to parasitic capacitance and stray resistance in the oscilloscope probe wires causing unexpected effects on the circuit.

Answer

In the RC circuit,    will spike, and in the RL circuit,    will spike. This phenomenon is only seen in practice and is not observed in simulation.

Answer

In the RC circuit,    will spike, and in the RL circuit,    will spike. This is because capacitors resist instantaneous changes in current, and inductors resist instantaneous changes in voltage.

Answer

In the RC circuit,    will spike, and in the RL circuit, the inductor current (  ) will spike. These spikes are due to the instantaneous change in the input, and theory predicts they will be infinite in magnitude.

Crowdly

A student performs two experiments. In the first experiment, they apply a squ...

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