Multiple choice question for engineering
Set 1
1. Grinding wheel is specified as “A 46 K 5 B 17”. Grain size of wheel will be
a) Coarse
b) Medium
c) Fine
d) Very Fine
Answer
Answer: b [Reason:] ’46’ represents grain size, which is medium grain size. Second value in the specification represents grain size.
2. Grinding wheel is specified as “C 8 K 5 B 17”. Grain size of wheel will be
a) Coarse
b) Medium
c) Fine
d) Very Fine
Answer
Answer: a [Reason:] ‘8’ represents grain size, which is coarse. Second value in the specification represents grain size.
3. Grinding wheel is specified as “A 600 K 5 B 17”. Grain size of wheel will be
a) Coarse
b) Medium
c) Fine
d) Very Fine
Answer
Answer: d [Reason:] ‘600’ represents grain size, which comes under very fine grain size. Second value in the specification represents grain size.
4. Which of the following grinding wheel will have fine grain size?
a) A 46 K 5 B 17
b) C 600 K 5 B 17
c) C 8 K 5 B 17
d) A 80 K 5 B 17
Answer
Answer: d [Reason:] Second place of ISO designation of grinding wheel represents grain size and “80” comes under fine rain size.
5. Which of the following grinding wheel will have fine grain size?
a) A 46 K 5 B 17
b) C 600 K 5 B 17
c) C 8 K 5 B 17
d) A 80 K 5 B 17
Answer
Answer: c [Reason:] Second place of ISO designation of grinding wheel represents grain size and “600” comes under very fine rain size.
6. Which of the following specified grinding wheel will have Aluminum oxide abrasive?
a) Z 46 K 5 B 17
b) C 600 K 5 B 17
c) C 8 K 5 B 17
d) A 80 K 5 B 17
Answer
Answer: d [Reason:] First place of ISO designation of grinding wheel represents grain type and “A” represents aluminum oxide.
7. Which of the following specified grinding wheel will have Zirconia abrasive?
a) Z 46 K 5 B 17
b) C 600 K 5 B 17
c) C 8 K 5 B 17
d) A 80 K 5 B 17
Answer
Answer: a [Reason:] First place of ISO designation of grinding wheel represents grain type and “Z” represents Zirconia.
8. Which of the following specified grinding wheel will have Silicon carbide abrasive?
a) Z 46 K 5 B 17
b) C 600 K 5 B 17
c) A 8 K 5 B 17
d) A 80 K 5 B 17
Answer
Answer: b [Reason:] First place of ISO designation of grinding wheel represents grain type and “C” represents silicon carbide.
9. Operation done to make periphery of grinding wheel concentric with its axis to recover its lost shape is known as
a) Loading
b) Glazing
c) Dressing
d) Trueing
Answer
Answer: d [Reason:] Trueing is done to make periphery of grinding wheel concentric with its axis and to recover its lost shape.
10. Removing dull grains in order to make grinding wheel sharp is known as
a) Loading
b) Glazing
c) Dressing
d) Trueing
Answer
Answer: c [Reason:] Dressing is done to make grinding wheel shaft by removing dull grains at top.
Set 2
1. Grain number of grinding wheel is ___ to grain size.
a) Directly proportional
b) Inversely proportional
c) Does not depend
d) None of the mentioned
Answer
Answer: b [Reason:] Grain number = 1/(grain size). Grain number is similar to density of grains on grinding wheels.
2. Which of the following is correct range for grain number of grinding wheel for coarse grains?
a) 220-600
b) 80-180
c) 30-60
d) 10-24
Answer
Answer: d [Reason:] For coarse grain, grain number ranges from 10 to 24.
3. Which of the following is correct range for grain number of grinding wheel for medium grains?
a) 220-600
b) 80-180
c) 30-60
d) 10-24
Answer
Answer: c [Reason:] For medium grain, grain number ranges from 30 to 60.
4. Which of the following is correct range for grain number of grinding wheel for fine grains?
a) 220-600
b) 80-180
c) 30-60
d) 10-24
Answer
Answer: b [Reason:] For fine grains, grain number ranges from 80 to 180.
5. Which of the following is correct range for grain number of grinding wheel for very fine grains?
a) 220-600
b) 80-180
c) 30-60
d) 10-24
Answer
Answer: a [Reason:] For very fine grains, grain number ranges from 220 to 600.
6. Which of the following grinding machine will give better result for rough machining?
a) Fine grain
b) Very fine grain
c) Coarse grain
d) None of the mentioned
Answer
Answer: c [Reason:] Coarse grain wheel will give better metal removal rate and space for chip removal as rate of chip flow in rough machining is high.
7. Which of the following grinding machine will give better result for finish machining operation?
a) Fine grain
b) Medium grain
c) Coarse grain
d) None of the mentioned
Answer
Answer: c [Reason:] Fine grain wheel will give smaller metal removal rate and hence better for finishing operations.
8. Which of the following symbols range of alphabet represent soft grain in grinding wheel?
a) A – H
b) I – P
c) Q – T
d) T – Z
Answer
Answer: a [Reason:] A-H represents soft grains in grinding wheel.
9. Which of the following symbols range of alphabet represent medium hardness grain in grinding wheel?
a) A – H
b) I – P
c) Q – T
d) T – Z
Answer
Answer: b [Reason:] I-P represents medium hard grains in grinding wheel.
10. Which of the following symbols range of alphabet represent hard grain in grinding wheel?
a) D – H
b) I – P
c) A – D
d) Q – Z
Answer
Answer: a [Reason:] A-H represents soft grains in grinding wheel.
Set 3
1. Rate of heat flow in conduction.
a) Is directly proportional to temperature gradient
b) Is inversely proportional to temperature gradient
c) Does not depend on temperature gradient
d) None of the mentioned
Answer
Answer: a [Reason:] Rate of heat flow in conduction is directly proportional to temperature gradient.
2. Thermal conductivity of silver in W/m-K is near about:
a) 210
b) 310
c) 410
d) 510
Answer
Answer: c [Reason:] Thermal conductivity of silver is near about 410 W/m-K. Rate of heat flow in conduction is directly proportional to temperature gradient.
3. Thermal conductivity of copper in W/m-K is near about:
a) 210
b) 385
c) 485
d) 510
Answer
Answer: b [Reason:] Thermal conductivity of copper is near about 385 W/m-K. Rate of heat flow in conduction is directly proportional to temperature gradient.
4. Thermal conductivity of aluminum in W/m-K is near about:
a) 202
b) 302
c) 410
d) 502
Answer
Answer: a [Reason:] Thermal conductivity of aluminum is near about 202 W/m-K. Rate of heat flow in conduction is directly proportional to temperature gradient.
5. Which of the following is also known as transport property?
a) Pressure
b) Thermal conductivity
c) Resistance
d) None of the mentioned
Answer
Answer: b [Reason:] Thermal conductivity of material is also known as transport property. Rate of heat flow in conduction is directly proportional to temperature gradient.
6. With the use of thermal grease contact resistance will
a) Increase
b) Decrease
c) Remains constant
d) None of the mentioned
Answer
Answer: d [Reason:] Thermal grease reduces contact resistance. Silicon oil is thermal grease which decreases contact resistance.
7. Silicon oil applied between two contact surfaces will
a) Increase contact resistance
b) Decrease contact resistance
c) Increase gap void
d) None of the mentioned
Answer
Answer: b [Reason:] Silicon oil is thermal grease which decreases contact resistance. Thermal grease reduces contact resistance.
8. When temperature of mercury liquid increases, its thermal conductivity
a) Decreases
b) Increase
c) Remains constant
d) None of the mentioned
Answer
Answer: a [Reason:] Thermal conductivity of liquid is inversely proportional to temperature. When temperature of mercury liquid increases, its thermal conductivity decreases.
9. When molecular weight of mercury liquid increases, its thermal conductivity
a) Decreases
b) Increase
c) Remains constant
d) None of the mentioned
Answer
Answer: a [Reason:] Molecular weight of liquid is inversely proportional to temperature. Thermal conductivity of liquid is inversely proportional to temperature.
10. Thermal conductivity of diamond is more than that of glass. It is because
a) Diamond has crystalline structure
b) Glass has non crystalline structure
c) Diamond and glass both have crystalline structure
d) None of the mentioned
Answer
Answer: a [Reason:] Crystalline structures have more thermal conductivity due to lattice vibration. Thermal conductivity of liquid is inversely proportional to temperature.
Set 4
1. Which of the following is hardest constituent of steel?
a) Ludeburite
b) Austenite
c) Bainite
d) Martensite
Answer
Answer: d [Reason:] Martensite has needle like structure and hence is hardest form of steel. Martensite has fine grain structure.
2. α-iron is obtained below which of the following given temperature in centigrade?
a) 1539
b) 768
c) 910
d) 1410
Answer
Answer: b [Reason:] Below 910 degree centigrade steel becomes α iron with BCC structure. It is one of the allotropic form of iron.
3. δ-iron is obtained above which of the following given temperature in centigrade?
a) 1539
b) 768
c) 910
d) 1410
Answer
Answer: d [Reason:] Above 1410 degree centigrade steel becomes δ iron with BCC structure. It is one of the allotropic form of iron.
4. γ-iron is obtained above which of the following given temperature in centigrade?
a) 1539
b) 768
c) 910
d) 1410
Answer
Answer: c [Reason:] Above 910 degree centigrade steel becomes γ iron with FCC structure. It is one of the allotropic form of iron.
5. Which of the following structure of steel is non magnetic in nature?
a) α
b) δ
c) γ
d) None of the mentioned
Answer
Answer: a [Reason:] α-iron have bcc structure and is magnetic in nature. It is one of the allotropic form of iron. Below 910 degree centigrade steel becomes α iron with BCC structure.
6. Annealing of steel is done to impart which one of the following property on steel?
a) Hardness
b) Toughness
c) Ductility
d) None of the mentioned
Answer
Answer: c [Reason:] Annealing is used to impart softness on steel which increases ductility of steel. Cooling rate is slow during annealing and hence furnace cooling is done
7. In Annealing cooling is done in which of the following medium?
a) Air
b) Water
c) Oil
d) Furnace
Answer
Answer: d [Reason:] Cooling rate is slow during annealing and hence furnace cooling is done. Annealing is used to impart softness on steel which increases ductility of steel.
8. In Normalizing cooling is done in which of the following medium?
a) Air
b) Water
c) Oil
d) Furnace
Answer
Answer: a [Reason:] Cooling rate is medium during normalizing and hence air cooling is done. It imparts hardness to iron and help in forminf fine grain structure.
9. Mild steel can be converted into high carbon steel by using which of the following process?
a) Annealing
b) Normalizing
c) Case hardening
d) None of the mentioned
Answer
Answer: c [Reason:] Case hardening increases carbon content of steel by adding some carbon to it. It imparts hardness to iron.
10. Hypoeutectoid steels on cooling during annealing process converts to:
a) Perlite
b) Cementite
c) Austenite
d) None of the mentioned
Answer
Answer: a [Reason:] Hypoeutectoid steels on cooling during annealing process converts to perlite. It have coarse grain structure.
Set 5
1. Vacancy defects in solids is a sub type of :
a) Point Imperfections
b) Line Imperfections
c) Volume Imperfection
d) Surface Imperfection
Answer
Answer: a [Reason:] One or more atomic sites are vacant in vacancy defect. Vacancy defects in solids is a sub type of point imperfections.
2. Substitution of foreign atom in the site of parent atom in crystal is a?
a) Vacancy defect
b) Substitution Impurity
c) Volume Imperfection
d) Vacancy defect
Answer
Answer: b [Reason:] In Substitution impurity, foreign atom takes the position of parent atom. Toatal number of atoms remains same after the defect.
3. Edge dislocation Imperfection is a sub type of:
a) Point Imperfections
b) Line Imperfections
c) Volume Imperfection
d) Surface Imperfection
Answer
Answer: b [Reason:] Edge is resembled with line. Edge dislocation Imperfection is a sub type of line imperfections. There is some changes in edge in this defect.
4. Displacement of ion from regular location to interstitial location is known as:
a) Vacancy defect
b) Line Imperfection
c) Schottky’s defect
d) Frenkel defect
Answer
Answer: d [Reason:] When ion of a crystal moves to some interstitial site from its original position inside the same crystal, it is called Frenkel defect.
5. When a pair of cation and anion is absent from crystal, it is called:
a) Vacancy defect
b) Line Imperfection
c) Schottky’s defect
d) Frenkel defect
Answer
Answer: c [Reason:] When cation and anion of a crystal are absent then it is called Schottky’s Defect. It does not change the overall charge on the material.
6. Which one of the following are not zero dimensional defects?
a) Vacancy defect
b) Substitution Imperfection
c) Schottky’s defect
d) Screw dislocation
Answer
Answer: d [Reason:] Zero dimensional defects are the other name of Point Imperfection. Vacancy defects in solids is a sub type of point imperfections.
7. Twin or Twinning is a category of:
a) Point Imperfections
b) Line Imperfections
c) Volume Imperfection
d) Surface Imperfection
Answer
Answer: d [Reason:] In Twinning Arrangement of atoms is such that one side of twin boundary is mirror replica of other side.
8. As grain size of metal increases, Strength of metal:
a) Decreases
b) Increases
c) Remains constant
d) None of the mentioned
Answer
Answer: a [Reason:] Strength of metal is inversely proportional to size of grain. Coarse are softer in nature while material having fine grain structure are hard in nature.
9. As grain size of metal increases, Ductility of metal:
a) Decreases
b) Increases
c) remains constant
d) None of the mentioned
Answer
Answer: b [Reason:] Ductility of metal is directly proportional to size of grain. As grain size of metal increases, Ductility of metal increases
10. Phenomenon of cross slip occurs in:
a) Point Imperfections
b) Line Imperfections
c) Volume Imperfections
d) Surface Imperfections
Answer
Answer: b [Reason:] Cross slip occurs in Screw dislocation which cause change in slip plane.