Two resistors in a row do more than slow the current, they carve up the voltage between them. Swap one for a light or heat sensor and the split shifts with the surroundings, the heart of an automatic switch.
A potential divider is two resistors in series that share the supply voltage in proportion to their resistances, with the output taken across one of them. Replacing one resistor with an LDR or thermistor makes the output voltage respond to light or temperature.
A potential divider is two resistors in series that split the supply voltage in the ratio of their resistances. The output is the voltage across one of them.
The larger share of the voltage appears across the larger resistance. A sensor as one resistor makes the output respond to light or temperature.
Change the two resistances and watch how the output voltage tracks their ratio.
Four quick checks. Each correct answer earns XP and lights this skill on your star map.
A potential divider splits the supply voltage in the ratio of...
The output of a potential divider is taken across...
In a potential divider the larger share of the voltage is across the...
Replacing one resistor in a divider with an LDR makes the output respond to...
Make one resistor a light or heat sensor and the output becomes a signal that responds to the surroundings.
A 12 V supply is across a 4.0 kΩ resistor in series with an 8.0 kΩ resistor. Find the output across the 8.0 kΩ resistor.
The larger share of the voltage appears across the larger resistance. The output across one resistor equals the supply voltage multiplied by that resistance divided by the total resistance.
Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.
A 12 V supply is across a 4.0 kΩ resistor in series with an 8.0 kΩ resistor. The voltage across the 8.0 kΩ resistor is...
In a potential divider, an LDR is in bright light so its resistance falls. The voltage across the LDR therefore...
Two equal resistors form a potential divider across a 9.0 V supply. The output across one of them is...
Potential dividers complete the circuits strand. Keep the chain going.