8/28/2011
GATE‐2007 A 200 mm long down sprue has an area of cross section of 650 mm2 where the pouring basin meets the down sprue (i.e. at the beginning of the down sprue). A constant head of molten metal is maintained by the p g basin. The Molten metal flow rate is 6.55 × 105 pouring mm3/s. Considering the end of down sprue to be open to atmosphere and an acceleration due to gravity of 104mm/s2, the area of the down sprue in mm2 at its end (avoiding aspiration effect) should be (a)650.0
(b)350.0
(c)290.7
(d)190.0
Compiled by: S K Mondal Made Easy
Ans. (c) Contd…
Compiled by: S K Mondal Made Easy
Gating ratio y Gating ratio is defined as: Sprue area: Runner area:
Ingate area. y For high quality steel castings, a gating ratio of 1: 2: 2 or
1: 2: 1.5 will produce castings nearly free from erosion, will minimize oxidation, and will produce uniform flow. y A gating ratio of 1: 4: 4 might favour the formation of
IES‐2003 A gating ratio of 1: 2: 4 is used to design the gating system for magnesium alloy casting. This gating ratio refers to the cross∙ section areas of the various gating elements as given below: 1. Down sprue 2. Runner bar 3. Ingates The correct sequence of the above elements in the ratio 1: 2: 4 is (a) 1, 2 and 3 (b) 1,3 and 2 (c) 2, 3 and 1 (d) 3, 1 an 2
Ans. (a)
oxidation defects. Compiled by: S K Mondal Made Easy
Compiled by: S K Mondal Made Easy
IES‐2005 The gating ratio 2: 8: 1 for copper in gating system design refers to the ratio of areas of: (a) Sprue: Runner: Ingate (b) Runner: Ingate: Sprue (c) Runner: Sprue: Ingate (d) Ingate: Runner: Sprue
GATE‐2010 In a gating system, the ratio 1:2:4 represents (a) Sprue base area: runner area: ingate area (b) Pouring basin area : ingate area : runner area (c) Sprue base area : ingate area : casting area (d) Runner area : ingate area : casting area
Ans. (a)
Ans. (a) Compiled by: S K Mondal Made Easy
Compiled by: S K Mondal Made Easy
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