EEC115
EEC 115 - Electrical Engineering Fundamentals
EEC 115 - Tushen Injiniyan Lantarki
Comprehensive Study Guide for ND1 Students
Jagorar Nazari Cikakke ga Daliban ND1
Ohm's Law and Basic Circuits
Dokar Ohm da Da'irori na Asali
Ohm's Law: States that current (I) is directly proportional to voltage (V) and inversely proportional to resistance (R).
Dokar Ohm: Ta bayyana cewa halin yanzu (I) yana daidai da ƙarfin lantarki (V) kuma yana saba wa juriya (R).
I = V / R
V = I × R
R = V / I
If V = 100V and I = 5mA, find R.
Idan V = 100V da I = 5mA, nemo R.
Step 1: Convert mA to A: I = 5 × 10⁻³ A = 0.005 A
Mataki na 1: Canza mA zuwa A: I = 5 × 10⁻³ A = 0.005 A
Step 2: Apply Ohm's Law: R = V / I = 100 / 0.005 = 20,000 Ω = 20 kΩ
Mataki na 2: Aiwatar da Dokar Ohm: R = V / I = 100 / 0.005 = 20,000 Ω = 20 kΩ
Important: Always ensure units are consistent (Volts, Amperes, Ohms) before applying Ohm's Law.
Muhimmi: Koyaushe tabbatar raka'a sun yi daidai (Volts, Amperes, Ohms) kafin a yi amfani da Dokar Ohm.
Series and Parallel Circuits
Da'irori na Jere da Na Kusa
Series Circuits
Da'irori na Jere
- Only one path for current flow
- Current is the same through all components
- Total resistance: Rtotal = R1 + R2 + R3 + ...
- Voltage divides across components
- Hanya ɗaya kawai don kwararar halin yanzu
- Halin yanzu yayi daidai a cikin duk abubuwan
- Jimlar juriya: Rtotal = R1 + R2 + R3 + ...
- Ƙarfin lantarki yana raba a kan abubuwan
Parallel Circuits
Da'irori na Kusa
- Multiple paths for current flow
- Voltage is the same across all components
- Total resistance: 1/Rtotal = 1/R1 + 1/R2 + 1/R3 + ...
- Current divides between branches
- Hanyoyi da yawa don kwararar halin yanzu
- Ƙarfin lantarki yayi daidai a kan duk abubuwan
- Jimlar juriya: 1/Rtotal = 1/R1 + 1/R2 + 1/R3 + ...
- Halin yanzu yana raba tsakanin rassan
Given R1 = 2.2Ω, R2 = 1.8Ω, and V = 12V, find voltage drops across each resistor.
An bayar da R1 = 2.2Ω, R2 = 1.8Ω, da V = 12V, nemo raguwar ƙarfin lantarki a kowane resistor.
Step 1: Calculate total resistance: RT = R1 + R2 = 2.2 + 1.8 = 4Ω
Mataki na 1: Lissafa jimlar juriya: RT = R1 + R2 = 2.2 + 1.8 = 4Ω
Step 2: Calculate current: I = V / RT = 12 / 4 = 3A
Mataki na 2: Lissafa halin yanzu: I = V / RT = 12 / 4 = 3A
Step 3: Calculate voltage drops: VR1 = I × R1 = 3 × 2.2 = 6.6V, VR2 = I × R2 = 3 × 1.8 = 5.4V
Mataki na 3: Lissafa raguwar ƙarfin lantarki: VR1 = I × R1 = 3 × 2.2 = 6.6V, VR2 = I × R2 = 3 × 1.8 = 5.4V
Resistivity and Conductivity
Juriya da Gudanarwa
Resistivity (ρ): The resistance of a material of unit length and unit cross-sectional area.
Juriya (ρ): Juriya na wani abu mai tsayi na raka'a da yanki na giciye na raka'a.
ρ = R × A / l
where: R = resistance, A = cross-sectional area, l = length
Conductivity (σ): The reciprocal of resistivity, measures how well a material conducts electricity.
Gudanarwa (σ): Ma'anar juriya, yana auna yadda wani abu yake gudanar da wutar lantarki.
σ = 1 / ρ
A wire of length 0.5m, diameter 0.5mm, has resistance of 2.5Ω. Calculate resistivity.
Waya mai tsayi 0.5m, diamita 0.5mm, yana da juriya 2.5Ω. Lissafa juriya.
Step 1: Calculate radius: r = 0.5mm / 2 = 0.25mm = 2.5 × 10⁻⁴ m
Mataki na 1: Lissafa radius: r = 0.5mm / 2 = 0.25mm = 2.5 × 10⁻⁴ m
Step 2: Calculate cross-sectional area: A = πr² = (22/7) × (2.5 × 10⁻⁴)² m²
Mataki na 2: Lissafa yankin giciye: A = πr² = (22/7) × (2.5 × 10⁻⁴)² m²
Step 3: Calculate resistivity: ρ = R × A / l = 2.5 × (22/7) × (2.5 × 10⁻⁴)² / 0.5 = 98.19 × 10⁻⁸ Ω·m
Mataki na 3: Lissafa juriya: ρ = R × A / l = 2.5 × (22/7) × (2.5 × 10⁻⁴)² / 0.5 = 98.19 × 10⁻⁸ Ω·m
Temperature Coefficient of Resistance
Ma'aunin Zafin Jiki na Juriya
Definition: The increase in resistance per original resistance at 0°C per temperature change.
Ma'ana: Ƙaruwar juriya a kowane juriya na asali a 0°C a kowane canjin zafin jiki.
α = (R₁ - R₀) / [R₀ × (θ₁ - θ₀)]
Rθ = R₀ (1 + αθ)
A coil has resistance of 50Ω at 0°C. If α = 0.0043/°C, find resistance at 25°C.
Coil yana da juriya 50Ω a 0°C. Idan α = 0.0043/°C, nemo juriya a 25°C.
Step 1: Apply formula: Rθ = R₀ (1 + αθ)
Mataki na 1: Aiwatar dabara: Rθ = R₀ (1 + αθ)
Step 2: Calculate: R25 = 50 × (1 + 0.0043 × 25) = 50 × (1 + 0.1075) = 50 × 1.1075 = 55.375Ω
Mataki na 2: Lissafa: R25 = 50 × (1 + 0.0043 × 25) = 50 × (1 + 0.1075) = 50 × 1.1075 = 55.375Ω
Kirchhoff's Laws
Dokokin Kirchhoff
Kirchhoff's Current Law (KCL)
Dokar Halin Yanzu ta Kirchhoff (KCL)
- The algebraic sum of currents entering a node is zero
- Sum of currents entering = Sum of currents leaving
- Based on conservation of charge
- Jimlar aljebra na halin yanzu da ke shiga wani kulli sifili ne
- Jimlar halin yanzu da ke shiga = Jimlar halin yanzu da ke fita
- Ya dogara ne akan kiyaye caji
Kirchhoff's Voltage Law (KVL)
Dokar Ƙarfin Lantarki ta Kirchhoff (KVL)
- The algebraic sum of voltages in any closed loop is zero
- Sum of EMFs = Sum of voltage drops
- Based on conservation of energy
- Jimlar aljebra na ƙarfin lantarki a kowane madauki sifili ne
- Jimlar EMFs = Jimlar raguwar ƙarfin lantarki
- Ya dogara ne akan kiyaye makamashi
Exam Tip: When applying KVL, follow a consistent direction (clockwise or anticlockwise) and assign proper signs to voltage sources and drops.
Shawarar Jarrabawa: Lokacin amfani da KVL, bi hanya mai daidaito (agogo ko kuma akasin agogo) kuma sanya alamomin da suka dace ga tushen ƙarfin lantarki da raguwa.
Electrostatics and Capacitance
Lantarki Mai Tsayi da Ƙarfin Ƙwaƙwalwa
Coulomb's Law: The force between two point charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.
Dokar Coulomb: Ƙarfin da ke tsakanin caji biyu yana daidai da samfurin cajinsu kuma yana saba wa murabba'in nisa tsakaninsu.
F = k × (Q₁ × Q₂) / d²
where k = 9 × 10⁹ N·m²/C² (in vacuum)
Capacitance: The ability of a capacitor to store electric charge.
Ƙarfin Ƙwaƙwalwa: Ƙarfin capacitor na adana cajin lantarki.
C = Q / V
Energy stored: W = ½ C V²
Capacitor Connections
Haɗin Capacitor
- Series: 1/Ceq = 1/C₁ + 1/C₂ + 1/C₃ + ...
- Parallel: Ceq = C₁ + C₂ + C₃ + ...
- Jere: 1/Ceq = 1/C₁ + 1/C₂ + 1/C₃ + ...
- Kusa: Ceq = C₁ + C₂ + C₃ + ...
SI Prefixes
Gaban SI
| Prefix | Gaban | Symbol | Multiplier |
|---|---|---|---|
| Tera | Tera | T | 10¹² |
| Giga | Giga | G | 10⁹ |
| Mega | Mega | M | 10⁶ |
| Kilo | Kilo | k | 10³ |
| Milli | Mili | m | 10⁻³ |
| Micro | Mikro | μ | 10⁻⁶ |
| Nano | Nano | n | 10⁻⁹ |
| Pico | Piko | p | 10⁻¹² |
Exam Preparation Tips
Shawarwari don Shirye-shiryen Jarrabawa
- Practice solving problems from both lecture notes and tutorials
- Understand the concepts rather than memorizing formulas
- Pay attention to units and ensure consistency in calculations
- Review circuit analysis methods (Ohm's Law, Kirchhoff's Laws)
- Practice with different circuit configurations (series, parallel, combination)
- Understand the physical meaning of electrical parameters
- Yi aiki kan warware matsaloli daga bayanan lacca da kuma darussan
- Fahimci ra'ayoyin maimakon haddace dabaru
- Kula da raka'a kuma tabbatar da daidaito a cikin lissafi
- Bita hanyoyin bincike na da'ira (Dokar Ohm, Dokokin Kirchhoff)
- Yi aiki tare da siffofin da'ira daban-daban (jere, kusa, haɗuwa)
- Fahimci ma'anar jiki na ma'auni na lantarki