MCQs on Mechanics of Cutting-1
1 - Question
Which of the following is correct about chip thickness ratio ‘r’?
a) r<1
b) r=1
c) r>1
d) None of the mentioned
View Answer
Explanation: Uncut chip thickness is always less than cut chip thickness and ‘r’ is the ratio of cut chip thickness to uncut chip thickness.
2 - Question
If t1 denotes the uncut chip thickness and t2 denotes cut chip thickness ratio then, which of the following equation is correct about chip thickness ratio ‘r’?
a) r=t1/t2
b) r=t1/t2
c) r=t1*t2
d) None of the mentioned
View Answer
Explanation: ‘r’ is the ratio of cut chip thickness to uncut chip thickness. Here t1 is the uncut chip thickness and t2 is the cut chip thickness.
3 - Question
Which of the following is the correct relation for chip thickness ratio ‘r’? Given that: φ=shear angle α=rake angle
a) tan φ= cosα/(1-r*sinφ)
b) tan φ= rcosα/(1-r*sinφ)
c) tan φ= rcosα/(1-sinφ)
d) tan φ= cosα/(r-r*sinφ)
View Answer
Explanation: Value of chip thickness ratio is given by: tan φ= rcosα/(1-r*sinφ) . ‘r’ is the chip thickness ratio, which is the ratio of cut chip thickness to uncut chip thickness. advertisement
4 - Question
Horizontal force exerted by tool on work piece is known as
a) Cutting force
b) Frictional resistance
c) Backing up force
d) Shear force
View Answer
Explanation: Cutting force is the force by which tool cut work piece in horizontal direction. It is responsible for the cutting action during machining.
5 - Question
Metal resistance to shear during chip formation is known as
a) Cutting force
b) Frictional resistance
c) Backing up force
d) Shear force
View Answer
Explanation: Metal resistance to shear in chip formation is known as shear plane. It acts on a shear plane. It cause distortion in shape and angle.
6 - Question
Force exerted by work piece on chip in normal direction of shear plane is known as
a) Cutting force
b) Frictional resistance
c) Backing up force
d) Shear force
View Answer
Explanation: Backing up force is the force exerted by work piece on chip in normal direction of shear plane. It does not cause any distortion or shape change.
7 - Question
Force exerted by tool on chip normal to tool face is known as
a) Cutting force
b) Frictional resistance
c) Backing up force
d) Shear force
View Answer
Explanation: Frictional resistance is the resistance offered between tool and chip interface. It causes generation of heat during welding.
8 - Question
Which of the following assumption is not valid for merchant circle diagram?
a) Continuous Chips
b) Discontinuous chips
c) Cutting edge remains sharp
d) No built up edge
View Answer
Explanation: Chips are assumed to be continuous in nature in drawing of merchant circle. In actual practice, thickness may not be uniform.
9 - Question
Which of the following assumption is not valid for the merchant circle diagram?
a) Continuous Chips
b) Sharpness of cutting edge reduces gradually
c) Cutting edge remains sharp
d) No built up edge
View Answer
Explanation: Sharpness of cutting edge is assumed to be constant during the cutting process. In actual machining process sharpness of cutting edge decreases as time passes.
10 - Question
Which of the following is correct equation for shear force FS=? φ is the shear angle?
a) FS=FCcosφ-FTsinφ
b) FS=FCcosφ/FTsinφ
c) FS=FCcosφ*FTsinφ
d) FS=FCcos&o#966;+FTsinφ
View Answer
Explanation: FS=FC cosφ-FT sinφ is the correct relation of shear force in terms of horizontal cutting force, Tangential cutting force and shear angle.