Questions & explanations
1. Compare the learner stage and the intermediate stage in GDL.
In the learner stage, you must drive with a supervising adult and cannot drive alone. In the intermediate stage, you can drive alone but with restrictions like no driving late at night and no passengers who are teens unless a family member. The learner stage focuses on practice with help, while the intermediate stage gives more freedom but still limits high-risk situations. The learner stage usually lasts longer, like 6-12 months, while the intermediate stage may last until a certain age or driving log hours. Both stages require you to avoid alcohol and wear seatbelts. After passing all requirements, you get a full license with no restrictions.
2. What is 'universal design' in public transit?
Universal design means designing transit vehicles, stations, and information so that everyone can use them easily, including people with disabilities. For example, buses with low floors allow wheelchair users to roll on without steps. Signs with large, clear text help people with poor vision. Audio announcements help people who cannot see the signs. Universal design goes beyond legal minimums to create inclusive spaces. It benefits not just people with permanent disabilities but also parents with strollers and travelers with luggage. The goal is to make transit usable by all without need for special adaptation.
3. What factor about the car's value affects insurance cost differently for lessees?
The car's depreciation affects insurance cost for lessees because the leasing company requires coverage for the full value. For owners, insurance is based on the car's current market value. But for lessees, the insurance must cover the initial higher value of the car. As the car depreciates, the required coverage stays high to match the lease balance. This means lessees pay more for insurance on a newer car compared to owners who can reduce coverage as the car ages. Also, some cars depreciate faster, increasing the gap and insurance risk. So lessees should consider depreciation rates when choosing a car.
4. After rotating tires, some TPMS systems need re-learning. Which type usually needs that? Explain.
Direct TPMS systems often need re-learning after tire rotation. Each sensor has a unique ID that the car's computer must match to the correct wheel position. When you rotate tires, the sensors move to a different corner, so the computer must learn the new positions. Some cars do this automatically after driving a short distance, while others require a manual reset tool. Indirect TPMS usually does not need re-learning after rotation because it only tracks wheel speed differences, not individual sensor IDs. However, some indirect systems may need a reset if the tires are significantly different in size.
5. Why is it hard to make a gasoline engine reach brake thermal efficiency above 40%?
Gasoline engines face several limits. They have lower compression ratios than diesels to avoid knocking, which reduces thermal efficiency. They also use throttling to control power, which creates pumping losses. Additionally, the stoichiometric air-fuel ratio (about 14.7:1) limits the expansion ratio. Heat losses through the cylinder walls and exhaust also drain energy. Advanced technologies like direct injection, turbocharging, and variable valve timing help, but the fundamental Otto cycle efficiency is about 30-35%. Reaching above 40% requires extreme measures like lean burn or Atkinson cycle.
6. What is one legal requirement for public transit to be accessible?
Many countries have laws that set minimum accessibility standards. For example, in the United States, the Americans with Disabilities Act (ADA) requires that all new buses be wheelchair accessible. In India, the Rights of Persons with Disabilities Act (2016) mandates accessible transport. Common requirements include low-floor boarding, priority seating, and audio-visual announcements. Transit agencies must also ensure that stations have ramps or elevators. These laws aim to give people with disabilities equal access to public transportation. Compliance is enforced through inspections and fines.
7. How can turbocharging improve brake thermal efficiency?
A turbocharger forces more air into the cylinders, allowing more fuel to be burned and producing more power from the same engine size. This improves the power-to-weight ratio and can increase brake thermal efficiency because the engine runs at higher loads where efficiency is better. Turbocharging also reduces pumping losses since the intake pressure is higher. By recovering some exhaust energy, it effectively recycles waste heat. However, it adds complexity and can cause knocking if not tuned properly. Overall, turbocharged engines often achieve higher BTE than naturally aspirated ones.
8. What role does the battery play in the Toyota Hybrid System during acceleration versus cruising?
During acceleration, the battery supplies additional electricity to the motor, supplementing the engine’s power. This gives extra torque for a few seconds. During cruising, the battery usually does not provide power unless the engine is not running efficiently. Instead, the generator may send surplus electricity to the battery to recharge. The system also uses the battery to store energy from regenerative braking. The battery acts as a buffer, smoothing out power demands so the engine can stay in its efficient zone. Its SOC is managed to be around 60% to allow both charge and discharge.
9. Why do many plug-in hybrids use a series-parallel configuration rather than a simple series or parallel?
Plug-in hybrids (PHEVs) need to run in electric-only mode for a range, then switch to hybrid mode for longer trips. A series-parallel configuration allows the electric motor to drive the wheels at low speeds without the engine on (electric-only). When the battery depletes, the system can operate in either series or parallel mode for best efficiency. It also lets the engine recharge the battery while driving. The added complexity is worth it because it offers the most flexibility. Series-parallel PHEVs can achieve low emissions in city driving while retaining high efficiency on highways.
10. How does a stated component warranty differ from an exclusionary one?
A stated component warranty only covers specific parts or systems mentioned in the contract. For example, it might list engine, transmission, and drivetrain. It does not cover anything not listed. In contrast, an exclusionary warranty covers everything except what is listed as excluded. So exclusionary is broader. Stated component warranties are cheaper because they cover less. They are also called 'named component' warranties. If you care about covering many items, an exclusionary warranty is better. But if you only want major components, a stated component warranty may be enough.
11. How does the well-to-wheel efficiency of a hydrogen fuel cell vehicle compare to a battery electric vehicle?
Currently, battery electric vehicles (BEVs) have better well-to-wheel efficiency than hydrogen fuel cell vehicles (FCVs). Producing hydrogen usually requires electricity (electrolysis), which loses about 30% energy. Then compressing and transporting hydrogen loses another 10–20%. The fuel cell itself converts hydrogen to electricity at about 60% efficiency. So overall WTW for FCVs is around 30–40%. BEVs charge batteries directly from the grid with 90% charging efficiency and 85–95% motor efficiency, giving WTW of 60–80% (depending on energy source). So BEVs use less total energy.
12. What are the first steps you should take if your brakes fail while driving?
First, do not panic. Take your foot off the accelerator. Pump the brake pedal hard and fast several times: sometimes this builds up pressure and the brakes work again. If the brakes still do not respond, downshift to a lower gear to slow the car using the engine. Then, gradually apply the emergency (parking) brake—pull it slowly to avoid locking the wheels. Steer the car toward a safe area, like a shoulder or open space. Turn on your hazard lights to warn other drivers. Once the car slows down, try to stop by gently rubbing the tires against a curb or guardrail if necessary.