Core Practical: Investigating & Testing Circuits Flashcards
All 4 cards in this deck
In the core practical to investigate how current varies with potential difference for a resistor, what is changed and what is measured?
A variable resistor is adjusted to change the p.d. Measure the p.d. across the resistor with a voltmeter in parallel and the current with an ammeter in series.
When testing series circuits, what happens to the brightness of a lamp when a second identical lamp is added in series?
The lamp is dimmer, because the total resistance is greater so the current is less and the p.d. across each lamp is shared.
True or false? Two identical lamps connected in parallel to a supply are brighter than the same two lamps connected in series to that supply.
True. In parallel each lamp has the full supply p.d. across it, so a bigger current flows through each lamp.
Why are series circuits often used to test components?
It is easy to change and measure the current and p.d. for the component, and then find its resistance using .