About this previous year paper
Automotive Electrical & Electronics (BAU061)
Section-Wise Important Questions & Study Notes
SECTION–A
(Attempt all questions | 2 × 7 = 14)
This section checks basic definitions and fundamentals.
Write 2–3 lines only for each answer.
(a) Ohm’s Law & Kirchhoff’s Law
Ohm’s Law: Current is directly proportional to voltage at constant temperature (V = IR).
Kirchhoff’s Laws: KCL deals with current at a junction; KVL deals with voltage in a closed loop.
(b) Types of Automotive Batteries (Any Four)
Lead-acid battery
AGM (Absorbent Glass Mat) battery
Gel battery
Lithium-ion battery
(c) Main Function of Starter Motor
The starter motor converts electrical energy from the battery into mechanical energy to crank the engine for starting.
(d) Difference Between DC and AC Generator
| DC Generator | AC Generator |
|---|---|
| Produces DC output | Produces AC output |
| Uses commutator | Uses slip rings |
| Older technology | Modern & efficient |
(e) Spark Plug and Its Role
A spark plug produces an electric spark to ignite the air-fuel mixture in petrol engines.
(f) Advantages of CAN Bus System (Any Two)
Reduces wiring complexity
Faster and reliable data communication between ECUs
(g) Types of Automotive Sensors (Any Two)
Oxygen (O₂) sensor Temperature sensor
Speed sensor Pressure sensor
SECTION–B
(Attempt any THREE | 7 × 3 = 21)
Write descriptive answers with headings and neat diagrams.
(a) Lead Acid Battery – Construction & Working
Explain: Plates (positive PbO₂, negative Pb)
Electrolyte (H₂SO₄) Container and separators
Working during charging and discharging reactions.
(b) Starter Motors – Construction & Types
Explain: DC series motor construction
Types: inertia starter, pre-engaged starter Mention advantages of pre-engaged starters.
(c) Alternator in Charging System
Explain: Rotor, stator, diode rectifier
Voltage regulation Why alternators replaced generators in modern vehicles
(d) Distributor-Less Ignition System (DIS)
Explain: Elimination of distributor
Use of crankshaft position sensor ECU-controlled ignition timing
Advantages: better efficiency, low maintenance
(e) Automotive Electronic Systems – Architecture & Functions
Explain: Sensors → ECU → Actuators
Role of microcontrollers Applications: engine control, safety, comfort systems
SECTION–C
(Attempt any ONE | 7 × 1 = 7)
(a) Battery Charging Techniques & Tests
Explain: Constant current charging
Constant voltage charging Trickle charging
Battery tests: Hydrometer test
Load test Voltage test
OR
(b) Maintenance of Automotive Batteries
Explain: Electrolyte level checking
Terminal cleaning Specific gravity checking
Safety precautions