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Mechanical IC Engine

Description: Mechanical Engineering, Mechanical IC Engine
Number of Questions: 25
Created by:
Tags: IC Engine Mechanical Engineering Mechanical IC Engine IC Engines GATE
Attempted 0/25 Correct 0 Score 0

On which thermodynamics cycle does the petrol engine work?

  1. Otto cycle

  2. Joule cycle

  3. Rankine cycle

  4. Stirling cycle


Correct Option: A
Explanation:

Otto cycle

In a four stroke cycle, the minimum temperature inside the engine cylinder occurs at the

  1. begining of suction stroke

  2. end of suction stroke

  3. begining of exhaust stroke

  4. end of exhaust stroke


Correct Option: A
Explanation:

In a four stroke cycle, minimum temperature inside the engine cylinder occurs at the begining of suction stroke.

In a four stroke cycle engine, the sequence of operation is

  1. suction, expansion, compression and exhaust

  2. suction, compression, expansion and exhaust

  3. expansion, compression, suction and exhaust

  4. compression, expansion, suction and exhaust


Correct Option: B
Explanation:

The correct option is option 2.

In a petrol engine, if diesel is used, then the engine will

  1. not run

  2. run more efficiently

  3. run at a high speed

  4. explode


Correct Option: A
Explanation:

Not run

The inlet valve of a four stroke cycle internal combustion engine remains open for

  1. 130 degrees

  2. 180 degrees

  3. 230 degrees

  4. 270 degrees


Correct Option: C
Explanation:

 230 degrees

Scavenging efficiency of a four stroke cycle diesel engine is

  1. below 50%

  2. 50% to 85%

  3. 85% to 95%

  4. 95% to 100%


Correct Option: D
Explanation:
  1. 95% to 100%

Air fuel ratio of the petrol engine is controlled by

  1. carburettor

  2. injector

  3. governor

  4. internal valves


Correct Option: A
Explanation:
  1. carburettor

High speed compression engines operates on

  1. otto cycle

  2. diesel cycle

  3. dual combustion cycle

  4. all of these


Correct Option: C
Explanation:

dual combustion cycle

Voltage required to produce spark across the gap between the sparking points is

  1. 2000 volts to 4000 volts

  2. 4000 volts to 6000 volts

  3. 10000 volts to 12000 volts

  4. 12000 volts to 25000 volts


Correct Option: D
Explanation:

12000 volts to 25000 volts

Loud pulsating noise in IC engine is

  1. detonation

  2. turbulence

  3. pre-ignition

  4. supercharging


Correct Option: A
Explanation:
  1. detonation

Octane no. of petrol, generally available is

  1. 20 to 40

  2. 40 to 60

  3. 60 to 80

  4. 80 to 100


Correct Option: D
Explanation:
  1. 80 to 100

Ignition quality of petrol is expressed by

  1. cetane number

  2. octane number

  3. calorific value

  4. none of these


Correct Option: B
Explanation:
  1. octane number

Ignition quality of diesel oil is expressed by

  1. cetane number

  2. octane number

  3. calorific number

  4. none of these


Correct Option: A
Explanation:
  1. cetane number

Cetane number of diesel oil is

  1. 20 to 25

  2. 25 to 30

  3. 30 to 40

  4. 40 to 55


Correct Option: D
Explanation:
  1. 40 to 55

The power actually developed by the engine cylinder of an IC engine is known as

  1. theoretical power

  2. actual power

  3. indicated power

  4. mechanical power


Correct Option: C
Explanation:
  1. Indicated power

Ratio of brake power to indicated power is known as

  1. mechanical efficiency

  2. overall efficiency

  3. indicated thermal efficiency

  4. volumetric efficiency


Correct Option: A
Explanation:
  1. mechanical efficiency

Morse test can be conducted for

  1. petrol engines

  2. diesel engines

  3. multi cylinder engines

  4. all of these


Correct Option: C
Explanation:
  1. multi cylinder engine

The thermal efficiency of a standard otto cycle for a compression ratio of 5.5 will be

  1. 25%

  2. 50%

  3. 70%

  4. 100%


Correct Option: B
Explanation:

The correct option is option 2.

A petrol engine has compression ratio

  1. 6 to 10

  2. 10 to 15

  3. 15 to 25

  4. 25 to 40


Correct Option: A
Explanation:
  1. 6 to 10

The pressure at the end of compression in a diesel engine is

  1. 10 bar

  2. 20 bar

  3. 25 bar

  4. 35 bar


Correct Option: D
Explanation:

The correct option is option 4.

A diesel engine has compression ratio from

  1. 6 to 10

  2. 10 to 15

  3. 15 to 25

  4. 25 to 35


Correct Option: C
Explanation:

15 to 25

The brake power is the power available

  1. in the engine cylinder

  2. at the crank shaft

  3. at the crank pin

  4. None of these


Correct Option: B
Explanation:

The break power is the power available at the crank shaft.

A diesel engine has

  1. one valve

  2. two valves

  3. three valves

  4. four valves


Correct Option: C
Explanation:

Three valves

In a petrol engine, the correct mixture of air and petrol is

  1. 10 : 1

  2. 15 : 1

  3. 20 : 1

  4. 25 : 1


Correct Option: B
Explanation:

The correct option is option 2.

The pressure at the end of compression in petrol engine is approximately

  1. 10 bar

  2. 20 bar

  3. 25 bar

  4. 35 bar


Correct Option: A
Explanation:

The correct option is option 1.

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