Physics Topic 2

Question 1

Charge Flow equation

Answer 1

Charge Flow=Current x Time
Q=It

Question 2

Voltage Equation

Answer 2

Voltage=Current x Resistance
V=IR

Question 3

How an LDR Works based on Intensity of light

Answer 3

An LDR is dependent on the intensity of the light. In bright light the resistance is low but in darkness it is very high.

Question 4

How a Thermistor works based of heat

Answer 4

A thermistor is dependent on the temperature in hot conditions the resistance is low but when cold it is high.

Question 5

Series Circuit Rules

Answer 5

1) if you remove or disconnect one component the circuit is broken
2) Voltage is shared: V total=V1+V2+V3…
3)Current is the same everywhere I1=I2=I3…
4)the size of the current is determined by the total voltage of the cells and the total resistance of the circuit I=V/R
Resistance add up: R total =R1+R2+R3…
This is because adding a resistor in series the two resistors have to share the total voltage
The voltage across each resistor is lower so the current through each resistor is also lower. In a series circuit the current is the same everywhere so the total current in the circuit is reduced when a resistor is added
The bigger a components resistance the bigger its share of the total voltage
There is a bigger voltage when cells are in series

Question 6

Parallels Circuit rules

Answer 6

If you remove or disconnect one loop/a component in one loop then the other loops are not affected
Voltage is the same across all loops V1=V2=V3….
Current is shared between branches I total=I1+I2….
Adding a resistor in parallel reduces the total resistance
If you have two resistors in parallel their total resistance is less than the resistance of the smallest of the two resistors
In parallel both resistors have the same voltage across them as the source, this means that the pushing force making the current flow is the same as the source voltage for each resister that you add.
V=IR I increases whilst R decreases and vice a versa