10.1 Flashcards
What is Kirchhoff’s second law
In a closed loop of an electrical circuit, the sum of the emfs is equal the sum of the pds
What is known about series circuits
• Current is the same in every position
• emf is shared between every component
-adding a component in series reduces the emf shared in other components (other loops) (including in parallel)
• Greater resistance will take more emf
• Multiple emf sources need to be totalled and the same rule applies
-If polarity is opposite then subtract (negative addition)
What is known about parallel circuits
- The current into each junction is equal to the current out of each junction
- Branches with greater resistance have lower currents
- if one has half resistance, twice current
- two-thirds of total current will run through other junction (ratio 2:1)
• Each branch is thought of as its own circuit
-If changes are made to one branch, others are unaffected
• The pd in each branch is the same as the emf
-if one branch contains multiple components then the sum of the pds in that loop equals the emf