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Mechanical Engineering MCQs with Explanations

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131Mechanical EngineeringMedium

Two pipe systems can be said to be equivalent, when the following quantities are same________?

Afriction factor and diameter

Blength and diameter

Cfriction loss and flow

Dflow and length

Evelocity and diameter

Correct answer

C. friction loss and flow

Explanation

The correct answer is friction loss and flow.

132Mechanical EngineeringMedium

Delta metal is an alloy of________?

Acopper, zinc and antimony

Bcopper, zinc and iron

Ciron, aluminium and magnesium

Diron, lead and tin

Eiron, nickel and copper

Correct answer

B. copper, zinc and iron

Explanation

The correct answer is copper, zinc and iron.

133Mechanical EngineeringMedium

Inertia force acts________?

Aopposite to the direction of ace ing force

Bnone of the above

Cin any direction w.r.t. accel* force depending on the magnit two

Dperpendicular to the accel< force

Ealong the direction of accel* force

Correct answer

A. opposite to the direction of ace ing force

Explanation

The correct answer is opposite to the direction of ace ing force.

134Mechanical EngineeringMedium

A tapered key which fits in a keyway in the hub and is flat on the shaft, is known as________?

Afeather key

Bgib head key

Cflat saddle key

Dwood-ruff key

Ehollow saddle key

Correct answer

C. flat saddle key

Explanation

The correct answer is flat saddle key.

135Mechanical EngineeringMedium

Leakage past the piston rings and valve seats in I.C. engines with increase in speed________?

Aunpredictable

Bdecreases

Cnone of the above

Dremains same

Eincreases.

Correct answer

B. decreases

Explanation

The correct answer is decreases.

136Mechanical EngineeringMedium

The pressure and temperature at the end of compression stroke in a petrol engine are of the order of________?

A4 – 6 kg/cm2 and 200 – 250°C

B6 – 12 kg/cm2 and 250 – 350°C

C20 – 30 kg/cm2 and 450 – 500°C

D30 – 40 kg/cm2 and 500 – 700°C

E12 – 20 kg/cm2 and 350 – 450°C

Correct answer

B. 6 – 12 kg/cm2 and 250 – 350°C

Explanation

The correct answer is 6 – 12 kg/cm2 and 250 – 350°C.

137Mechanical EngineeringMedium

A pressurised water reactor employs pressuriser for the following application________?

Ato maintain constant pressure in primary circuit under varying load

Bto provide subcooled water at high pressure

Cto increase pressure of water in primary circut

Dto Supply high pressure steam

Eall of the above

Correct answer

A. to maintain constant pressure in primary circuit under varying load

Explanation

The correct answer is to maintain constant pressure in primary circuit under varying load.

138Mechanical EngineeringMedium

Out of the following, from where you will prefer to take intake for air compressor________?

Afrom a side where cooling tower is located nearby

Bfrom outside atmosphere at 1°C

Cfrom any one of the above locations

Dfrom an air conditioned room maintained at 20°C

Efrom coal yard side

Correct answer

A. from a side where cooling tower is located nearby

Explanation

The correct answer is from a side where cooling tower is located nearby.

139Mechanical EngineeringMedium

Ferromagnetic alpha iron exists in temperature range of________?

A770 – 910°C

B1400-1539°C

C910-1440°C

Dbelow 723°C

Eabove 1539°C

Correct answer

D. below 723°C

Explanation

The correct answer is below 723°C.

140Mechanical EngineeringMedium

Pick up the wrong statement?

AMost serious drawback in using water as coolant in nuclear plants is its high vapour pressure

BIn a heterogeneous or solid-fuel reactor, the fuel is mixed in a regular pattern within moderator.

CFast neutrons have energies above 1000 eV

DSlow or thermal neutrons have energy of the order or 0.025 eV

EFast reactor uses moderator

Correct answer

E. Fast reactor uses moderator

Explanation

The correct answer is Fast reactor uses moderator.

Inertia force acts________?

Aopposite to the direction of ace ing force

Bnone of the above

Cin any direction w.r.t. accel* force depending on the magnit two

Dperpendicular to the accel< force

Ealong the direction of accel* force

Correct answer

A. opposite to the direction of ace ing force

Explanation

The correct answer is opposite to the direction of ace ing force.

A pressurised water reactor employs pressuriser for the following application________?

Ato maintain constant pressure in primary circuit under varying load

Bto provide subcooled water at high pressure

Cto increase pressure of water in primary circut

Dto Supply high pressure steam

Eall of the above

Correct answer

A. to maintain constant pressure in primary circuit under varying load

Explanation

The correct answer is to maintain constant pressure in primary circuit under varying load.

Out of the following, from where you will prefer to take intake for air compressor________?

Afrom a side where cooling tower is located nearby

Bfrom outside atmosphere at 1°C

Cfrom any one of the above locations

Dfrom an air conditioned room maintained at 20°C

Efrom coal yard side

Correct answer

A. from a side where cooling tower is located nearby

Explanation

The correct answer is from a side where cooling tower is located nearby.

Pick up the wrong statement?

AMost serious drawback in using water as coolant in nuclear plants is its high vapour pressure

BIn a heterogeneous or solid-fuel reactor, the fuel is mixed in a regular pattern within moderator.

CFast neutrons have energies above 1000 eV

DSlow or thermal neutrons have energy of the order or 0.025 eV

EFast reactor uses moderator

Correct answer

E. Fast reactor uses moderator

Explanation

The correct answer is Fast reactor uses moderator.