Materials Science and Manufacturing Engineering Miscellaneous

Materials Science and Manufacturing Engineering Miscellaneous

Easy Questions
Moderate Questions
Difficult Questions

Materials Science and Manufacturing Engineering

Materials Science and Manufacturing Engineering Miscellaneous
  1. The strength of a brazed joint








  1. View Hint View Answer Discuss in Forum

    Strength increases up to some certain gap and beyond this strength decreases.

    Correct Option: D

    Strength increases up to some certain gap and beyond this strength decreases.

  1. For spot welding of two steel sheets (base metal) each of 3 mm thickness, welding current of 10000 A is applied for 0.2 s. The heat dissipated to the base metal is 1000 J. Assuming that the heat required for melting 1 mm³ volume of steel is 20 J and interfacial contact resistance between sheets is 0.0002 ohms, the volume (in mm³) of weld nugget is.








  1. View Hint View Answer Discuss in Forum

    Heat required = 20 J/mm³
    I = 10000 A
    R = 0.0002Ω
    t = 0.2 sec
    H = I² R t
    = (10000)² × 0.0002 × 0.2 = 4000 Joules
    Heat Required to melt the nugget
    = 4000 – 1000 = 3000 Joules
    Volume of Nugget = 3000/3 = 150mm³

    Correct Option: C

    Heat required = 20 J/mm³
    I = 10000 A
    R = 0.0002Ω
    t = 0.2 sec
    H = I² R t
    = (10000)² × 0.0002 × 0.2 = 4000 Joules
    Heat Required to melt the nugget
    = 4000 – 1000 = 3000 Joules
    Volume of Nugget = 3000/3 = 150mm³

  1. In a cutting test with 0.3 mm flank wear as tool failure criterion, a tool life of 10 min was obtained at a cutting velocity of 20 m/min. Taking tool life exponent as 0.25, the tool life in minutes at 40 m/min of cutting velocity will be








  1. View Hint View Answer Discuss in Forum

    n = 0.25 V1 = 20m /min,
    T1 = 10 min V2 = 40m/min, T2 =?
    V1Tn1 = V2Tn2 = C
    20 (T0)0.25 = 40 (T2)0.25
    T2 = 0.625 min

    Correct Option: B

    n = 0.25 V1 = 20m /min,
    T1 = 10 min V2 = 40m/min, T2 =?
    V1Tn1 = V2Tn2 = C
    20 (T0)0.25 = 40 (T2)0.25
    T2 = 0.625 min

  1. A workpiece of 2000 mm length and 300 mm width was machined by a planning operation with the feed set at 0.3 mm/stroke. If the machine tool executes 10 double strokes/min, the planning time for a single pass will be








  1. View Hint View Answer Discuss in Forum

    l = 2000 mm
    w = 300 mm
    f = 0.3 mm/ stroke
    No. of stroke = 2 × 10
    = 20 stroke/ min {double stroke}

    Total Machining time =
    2000
    		 = 100 min
    20

    Correct Option: B

    l = 2000 mm
    w = 300 mm
    f = 0.3 mm/ stroke
    No. of stroke = 2 × 10
    = 20 stroke/ min {double stroke}

    Total Machining time =
    2000
    		 = 100 min
    20

  1. In a single pass turning operation the cutting speed is the only variable based on the cutting time cost and the cutting edge cost. The tool life for minimum cost given that cost of 1 cutting edge is Rs. 5, operator wages including the machine tool cost is Rs. 75/hour and tool life equation is VT0.1 is 100








  1. View Hint View Answer Discuss in Forum

    Topt =
    1
    		 - 1Tc
    n

    Tc1 = 5
    n =
    5
    		 =
    5
    75
    		1.25
    100

    n = 4 rs/piece
    Topt =
    1 - 0.1
    		 × 4
    0.1

    Topt 36 min

    Correct Option: D

    Topt =
    1
    		 - 1Tc
    n

    Tc1 = 5
    n =
    5
    		 =
    5
    75
    		1.25
    100

    n = 4 rs/piece
    Topt =
    1 - 0.1
    		 × 4
    0.1

    Topt 36 min