circuits

Question 1

what happens when resistors are added in parallel

Answer 1

their combined resistance decreases and is, therefore, less than the resistance of the individual components

For example, If two resistors of equal resistance are connected in parallel, then the combined resistance will halve

Question 1

current in a series vs parallel circuit

Answer 1

• In a series circuit, the current is the same for all components
• In a parallel circuit, the current is split across the different branches (or junction). The total current into a junction must equal the total current out of a junction
• The amount of current in each branch depends on the total resistance of the components within that branch

Question 2

potential difference in a series vs parallel circuit

Answer 2

• In a series circuit, the e.m.f of the power supply is shared amongst all the components in different amounts, depending on their resistance
• In a parallel circuit, the voltage of all the components in each branch is equal to the e.m.f of the power supply

Question 3

what is Kirchhoff’s First Law

Answer 3

The sum of the currents entering a junction always equal the sum of the currents out of the junction

Question 4

def of a junction and branch

Answer 4

• A junction is a point where at least three circuit paths meet
• A branch is a path connecting two junctions

Question 5

what is Kirchhoff’s Second Law

Answer 5

The total e.m.f. in a closed circuit equals the sum of the potential differences across each component

Question 6

voltage in a series vs parallel circuit

Answer 6

• In a series circuit, the voltage is split across all components depending on their resistance
  The sum of the voltages is equal to the total e.m.f of the power supply
• In a parallel circuit, the voltage is the same across each closed loop
  The sum of the voltages in each closed circuit loop is equal to the total e.m.f of the power suppl

Question 7

what are the purposes of potential dividers

Answer 7

To provide a variable potential difference
To enable a specific potential difference to be chosen
To split the potential difference of a power source between two or more components

Question 8

uses of a thermistor circuit

Answer 8

A thermistor circuit is used in fire alarms, ovens and digital thermometers

Question 9

Potential divider equation and diagram

Answer 9

Question 10

potential divider definition

Answer 10

A combination of resistors in series connected across a voltage source

Question 11

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Question 12

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Question 13

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Question 14

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Question 15

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Question 16

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Question 17

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Question 18

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Question 19

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Question 20

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Question 22

Answer 22