From 54aac5101e6f5654128a84a4a3d693387fc37405 Mon Sep 17 00:00:00 2001 From: James Su Date: Thu, 6 Jun 2019 18:46:06 +0000 Subject: [PATCH] Update Unit_4_Physics_Study_Sheet.md --- .../SNC1DZ/Unit_4_Physics_Study_Sheet.md | 41 ++++++++++++++++++- 1 file changed, 39 insertions(+), 2 deletions(-) diff --git a/Grade 9/Science/SNC1DZ/Unit_4_Physics_Study_Sheet.md b/Grade 9/Science/SNC1DZ/Unit_4_Physics_Study_Sheet.md index 02f93af..16c3cfc 100644 --- a/Grade 9/Science/SNC1DZ/Unit_4_Physics_Study_Sheet.md +++ b/Grade 9/Science/SNC1DZ/Unit_4_Physics_Study_Sheet.md @@ -288,6 +288,20 @@ - `Everything` has resistance. Conductor has low resistnace. Insulator has high resistance. - Example: wire has an resistnace so low that it is ignored in many calculations. +## Factors Affecting The Resistance of Wires +- ### 1. Type of Material + - Copper has much less resistance than iron. + - **Analogy**: Water flowing through a pipeful of gravel. Resistance depends on type of gravel. +- ### 2. Length of Wire + - `Longer` wires have more resistance. + - **Analogy**: Water flowing through a pipeful of gravel. Resistance depends on length of pipe. +- ### 3. Thickness + - `Narrower` wires have more resistance. + - **Analogy**: Water flowing through a pipeful of gravel. Resistance depends on diameter of pipe. +- ### 4. Temperature + - `Higher temperature` gives more resistance (More particles moving around and blocking it). + - A hot filament has more resistance tahn a cold filament because atoms in the hot filament vibrate more and the vibration increases the resistance. + ## Product Efficiencies - Simply take the output / input x 100 and you get the percentage of the efficiency of your product. @@ -300,10 +314,33 @@ - $`I_T = I_1 = I_2 = I_3 \cdots = I_N`$ - $`V_T = V_1 + V_2 + V_3 \cdots + V_N`$ - $`R_T = R_1 + R_2 + R_3 \cdots + R_N`$ +- As **MORE** loads are added: + - $`R_T`$ `increases` because more loads are added. + - $`I_T`$ `decreases` because $`R_T`$ increases. + - $`I_{load}`$ `decreases` because voltage and resistance are the same for each load. + - $`V_{load}`$ `decreases` because each load gets `less` voltage ($`V`$) ($`V_T`$ supplied by battery gets divided by more loads). + - Each light bulb has the `less brightness` **(because brightness depends on voltage)** (Less energy gets converted into heat and light in each light bulb). ## Parallel Circuits - In a parallel circuit, there are also a set of rules where the current, voltage, and resistance follow. The current and voltage rules are swapped in this case. - $`I_T = I_1 + I_2 + I_3 \cdots + I_N`$ - $`V_T = V_1 = V_2 = V_3 \cdots = V_N`$ -- $`R_T = R_1^{-1} + R_2^{-1} + R_3^{-1} \cdots + R_N^{-1}`$ (I think). -- $`R_T = (R_1*R_2)/(R_1 + R_2)`$ \ No newline at end of file +- $`R_T = (R_1^{-1} + R_2^{-1} + R_3^{-1} \cdots + R_N^{-1})^{-1}`$ (I think). +- $`R_T = (R_1 \times R_2)/(R_1 + R_2)`$ +- As **MORE** loads are added: + - $`R_T`$ `decreases` because more loads are added. + - $`I_T`$ `increases` because $`R_T`$ decreases. + - $`I_{load}`$ `stays the same` because voltage and resistance are the same for each load. + - $`V_{load}`$ `stays the same` because each load gets the same voltage as before. + - Each light bulb has the `same brightness` **(because brightness depends on voltage)**. + +## Comparing Series And Parallel Circuits + +|Series Circuits|Parallel Circuits| +|:--------------|:----------------| +|- An electric circuit in which the compoenents are arranged one after another.
- It has only `one` path along which electrons can flow.
- If that path is interrupted, the whole circuit `stops`.|- An electric circuit in which the parts are arranged so that electrons can flow along `more` than one path.
- An interruption in one path `does not affect` the other path in the circuit| +|**Voltage (V):**
- Total voltage is determined by the battery used
- Each load uses `portion` of the total voltage supplied by the battery
- As the number of loads `increases`, the potiental difference (voltage) for each load `decreases`|**Voltage (V):**
- Total voltage is determined by the battery used
- Voltage across parallel resistors will always be `the same`, even if the resistors have `different` values
- As the number of loads `increases`, the potiental difference (voltage) for each load `stays the same`| +|**Current (I):**
- The current is the `same` throughout a series circuit
- As the number of loads `increases`, the total current `decreases`|**Current (I):**
- Each load uses `portion` of the total current from the battery
- As the number of loads `increases`, the total current `increases`| +|**Resistance (R):**
- Total resistance `increases` when more resistors / loads are added
- As the number of loads `increases`, the total resistance `increases`|**Resistance (R):**
- Total resistance `decreases` when more resistors / loads are added
- As the number of loads `increases`, the total resistance `decreases`| + +