Lecture 5: Effect of Rheostat and Circuit Voltage Analysis

Vocabulary flashcards covering the effects of varying a rheostat, series and parallel rules, and voltmeter behaviors across batteries and resistors based on Lecture 5.

Effect of Rheostat ($R_V$) Increase

When the variable resistance increases ($R_V \uparrow$), the equivalent resistance increases ($R_{eq} \uparrow$) and the total current decreases ($I_T \downarrow$).

Series Circuit

A circuit configuration characterized by having the same current ($\text{Same } I$) throughout, meaning there is only $1$ current ($1\,I$).

Voltmeter on Battery with No Resistance ($r = 0$)

A condition where the voltmeter reading across the battery is constant, experiencing no opposing effect from the total current ($I_T$).

Voltmeter on Battery with Internal Resistance ($r$)

A reading governed by $V_T = V_B - I_T r$, where the terminal voltage ($V_T$) opposes the total current ($I_T$) because the negative sign switches the directional arrow.

Voltmeter of the Constant Resistor ($V_{Rc}$)

A voltage reading determined by $V = I R_c$ where $R_c$ is constant, causing the voltage across the constant resistor to follow the current ($I_{Rc}$).

Voltmeter on Variable Resistor with Battery Resistance

A condition where a resistance ($r$ or $R$) exists in series with the battery; $R_V$ wins the argument, causing the voltage ($V_{Rv}$) to follow $R_V$.

Voltmeter on Variable Resistor with Zero Battery Resistance ($r = 0$)

A condition (1 against 1) where no factor wins because the change in current cancels the change in resistance ($I R_V$ cancels $R_V$), causing $V_{Rv}$ to remain constant.

Parallel Circuit

A circuit arrangement characterized by branching paths that have different currents ($\text{Different } I$).