Automobile Engineering Multiple Choice Questions on “Nonconventional Engines”.
1. What is a dual fuel engine?
a) The engine which uses gaseous and liquid fuel
b) The engine which uses two liquid fuels
c) The engine which uses two gaseous fuels
d) The engine which uses one liquid and any other fuel
Answer: a
Clarification: The duel fuel engine uses gaseous and liquid fuel. The dual-fuel engine works on the diesel cycle. The gaseous fuel is called the primary fuel. The mixture of air and gaseous fuel is compressed in the cylinder.
2. Which of the following has the same combustion as HCCI (Homogeneous Charge Compression Ignition) engine?
a) SI engine
b) CI engine
c) Hybrid of both SI and CI engine
d) Wankel engine
Answer: c
Clarification: HCCI engine has the same combustion as a hybrid of both SI and CI engine. HCCI is a form of IC engine in which well-mixed fuel and air are compressed to the auto-ignition temperature of the fuel.
3. Which of the following is true for the HCCI engine?
a) Emits high NOx and soot
b) Have a large power range
c) Efficiency is comparatively less
d) Pre-catalyst hydrocarbon emissions are higher
Answer: d
Clarification: Pre-catalyst hydrocarbon emissions are higher is one of the disadvantages of the HCCI engine. The advantages of the HCCI engine are NOx and soot emissions are almost negligible.
4. For which of the following engine lean-burn concept is ideal?
a) CI engine
b) SI engine
c) Free piston engine
d) Wankel engine
Answer: b
Clarification: SI engines are more ideal for the lean-burn concept. A lean-burn mode is a way to reduce throttling losses. In SI engine, the power is reduced by partially closing a throttle.
5. By which technique can the charge stratification be achieved?
a) Injection
b) Carburetion
c) Lean burn technology
d) Injection as well as carburation
Answer: d
Clarification: The charge stratification can be achieved by injection as well as carburation. Charge stratification means providing different fuel-air mixture strengths at various places in the combustion chamber.
6. Which of the following is true for stratified charge engine?
a) More prone for knock
b) Multi-fuel capabilities
c) More throttling losses
d) Overall rich mixture
Answer: b
Clarification: Multi-fuel capabilities are one of the advantages of the stratified charge engine. The stratified engines are developed to combine both advantages of diesel and petrol engines.
7. What is true about the Wankel engine?
a) It is a rotary external combustion engine
b) It is more expensive
c) It has a longer operating cycle
d) It has less time to complete the combustion
Answer: c
Clarification: Wankel engine is a type of internal combustion engine using rotary design to convert pressure into a rotating motion. It does not make use of reciprocating pistons.
8. Where is the variable compression ratio used?
a) SI engine
b) CI engine
c) Wankel engine
d) HCCI engine
Answer: a
Clarification: Variable compression is used in SI engines. There are several methods for changing both the geometric and effective compression ratio.
9. Which of the following is true for stratified charge engine?
a) More prone for knock
b) It uses an overall rich mixture
c) It has a lot of throttling losses
d) It has multi-fuel capabilities
Answer: d
Clarification: Stratified charge engine has multi-fuel capabilities. The advantages of a stratified charge engine are higher thermodynamic efficiency and reduced air pollution.
10. Which of the following is true about the Stirling engine?
a) High efficiency
b) Quiet operation
c) Compatible with alternative and renewable energy
d) High efficiency, quiet operation and compatible with renewable energy
Answer: d
Clarification: The Stirling engine has high efficiency. A Stirling engine is a heat engine operating on cyclic compression and expansion of air or any other fluid.