Design of Gating System MCQ Quiz - Objective Question with Answer for Design of Gating System - Download Free PDF

Last updated on May 29, 2025

Latest Design of Gating System MCQ Objective Questions

Design of Gating System Question 1:

In a sand casting process, a sprue of 10 mm base diameter and 200 mm height leads to a runner which fills a cubical cavity of 100 mm side. What will be the volume flow rate of metal? [Acceleration due to gravity = 10 m/s2, π = 3.14]

  1. 157 mm3/s
  2. 1570 mm3/s
  3. 15700 mm3/s
  4. 157000 mm3/s

Answer (Detailed Solution Below)

Option 4 : 157000 mm3/s

Design of Gating System Question 1 Detailed Solution

Concept:

The volume flow rate of metal in a sand casting process can be determined using Torricelli’s theorem, which states that the velocity of fluid flow under gravity is:

v=2gh

The volume flow rate Q is given by:

Q=Av

where:

  • A = Cross-sectional area of the sprue
  • v = Velocity of the molten metal

Given:

  • Diameter of sprue base: d = 10 mm
  • Height of sprue: h = 200 mm
  • Acceleration due to gravity: g = 10 m/s²
  • π = 3.14

Calculation:

Step 1: Compute velocity using Torricelli’s theorem

v=2gh=2×10×0.2

v=4=2 m/s

Step 2: Compute cross-sectional area of the sprue

A=πd24=3.14×(10×103)24

A=3.14×100×1064=7.85×106 m2

Step 3: Compute volume flow rate

Q=Av=(7.85×106)×2

Q=15.7×106 m3/s

Converting to mm³/s:

Q=15700 mm3/s

 

Design of Gating System Question 2:

Which of the following gating system components is the most critical that controls the rate of entry of metal into mold?

  1. Pouring basin
  2. Sprue
  3. Gate-on/Gate
  4. Runner

Answer (Detailed Solution Below)

Option 3 : Gate-on/Gate

Design of Gating System Question 2 Detailed Solution

Explanation:

Gating System Components in Metal Casting

  • In metal casting, the gating system is a crucial part of the mold design that controls how molten metal flows into the mold cavity. The gating system includes several components, such as the pouring basin, sprue, runner, and gate-on, each serving a specific function to ensure the proper filling of the mold.

Working Principle:

  • The gating system guides the molten metal from the ladle to the mold cavity.
  • The design of the gating system significantly affects the quality of the final cast product by controlling the flow rate, minimizing turbulence, and preventing defects such as air entrapment, slag inclusions, and cold shuts.

Components:

  • Pouring Basin: This is the initial reservoir where molten metal is poured. It allows for a smooth and controlled flow of metal into the sprue, reducing turbulence and preventing air entrapment.
  • Sprue: The sprue is a vertical channel that directs the molten metal from the pouring basin to the runner. It prevents the formation of vortexes that can trap air and inclusions.
  • Runner: The runner is a horizontal channel that distributes the molten metal from the sprue to various gates. It helps in maintaining a consistent flow rate and minimizing turbulence.
  • Gate-on: The gate-on (or simply gate) is the entry point through which the molten metal enters the mold cavity. Proper design of the gate ensures even filling of the mold and reduces the chances of defects. It controls the rate of entry of metal into the mold.

Design of Gating System Question 3:

What is the purpose of a pattern in the casting pattern procedure? 

  1. To clean the mould before casting 
  2. To pour molten metal into the mould cavity
  3. To create the mould cavity 
  4. To remove the casting from the mould

Answer (Detailed Solution Below)

Option 3 : To create the mould cavity 

Design of Gating System Question 3 Detailed Solution

Explanation:

Casting Pattern Procedure:

  • The pattern is a replica of the object to be cast, used to form the cavity in the sand.
  • It is a crucial element in the casting process as it determines the shape and size of the final cast product.

Let us understand the role of a pattern in the casting process:

Purpose of a Pattern:

  • The primary purpose of a pattern is to create the mould cavity where the molten metal will be poured.
  • The pattern is placed in the sand to create an impression, which forms the mould cavity.
  • Once the pattern is removed, the cavity retains the shape of the pattern, ready to be filled with molten metal.

Additional Information

There are different types of patterns used in casting, such as:

  • Single-piece pattern: Used for simple shapes.
  • Split pattern: Used for complex shapes, split into two or more parts.
  • Match plate pattern: Both halves of the pattern are mounted on a plate.
  • Cope and drag pattern: Similar to split pattern but specifically for cope (top half) and drag (bottom half) parts of the mould.

Design of Gating System Question 4:

The length of a mold sprue is 45 cm and the cross-sectional area at its base is 5 cm2. The sprue feeds a horizontal runner leading into a mold cavity whose volume is 3000 cm3. Determine the time to fill the mold. Assume, gravity, g = 10 m/s2.

  1. 1 s
  2. 2 s
  3. 10 s
  4. 20 s

Answer (Detailed Solution Below)

Option 2 : 2 s

Design of Gating System Question 4 Detailed Solution

Concept:

For calculating Time (t) to fill the mould cavity we must know the discharge (Q) through the gate, as the amount of molten metal discharged through gate falls into the mould cavity.

Qgate = Agate × Vgate

where, 

Qgate = Discharge from the gate.

Agate = Area of gate

Vgate=Velocityatthegate=2ghSprue

Qgate × t = Volume of Mould

t=VolumeofmouldcavityAg2ghsprue

Calculation:

Given:

hsprue = 45 cm,  Asprue = 5 cm2, Volume of mould = 3000 cm3, g = 10 m/s2 ⇒ 1000 cm/s2

t=VolumeofmouldcavityAg2ghsprue

t=30005×2×1000×45

t = 3000 / (5 x 300) = 2 sec

Design of Gating System Question 5:

In order to stop the debris from going into the main casting cavity _____ is used. 

  1. skim bob 
  2. down gate 
  3. sprue
  4. pouring basin 

Answer (Detailed Solution Below)

Option 1 : skim bob 

Design of Gating System Question 5 Detailed Solution

Explanation:

Skim bob: 

  • It is an enlarged section at some place along the runner. This helps in trapping impurities such as dross of eroded sand and thus prevents them from going into the mould cavity. Both light and heavy impurities are trapped by the skim bob.

F1 S.S Madhu 24.12.19 D1

Sprue: 

  • The passage through which the molten metal from the pouring basin reaches the mould cavity. In many cases, it controls the flow of metal into the mould.

Pouring Basin:

  • Pouring Basin acts as are reservoir from which molten metal moves smoothly into the sprue. The pouring basin stops the debris from going into the main casting by means of a skimmer or skim bob.

Top Design of Gating System MCQ Objective Questions

The part of a gating which regulates the rate of pouring of molten metal is 

  1. pouring basin
  2. runner
  3. choke
  4. ingate

Answer (Detailed Solution Below)

Option 3 : choke

Design of Gating System Question 6 Detailed Solution

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F1 V.S M.P 26.09.19 D2

Pouring Basin →

→ Pouring Basin act as are reservoir from which molten metal moves smoothly into the sprue.

→ Pouring basin stop slag from entering the mould cavity by means of a skimmer or skim bob.

F1 S.S Madhu 24.12.19 D1

→ The depth of the pouring basin is 2.5 times the sprue entrance diameter for smooth metal flow and to prevent vortex formation:

Runner:

→ It is generally located in a horizontal plane (parting plane) which connects the sprue to its ingates, thus, allowing the metal to enter the mould cavity.

Ingate (Gate):

→ These are the opening through which molten metal enters the mould cavity.

→ The shape and cross-section of the ingate should be such that it can readily be broken off after casting solidification and also to allow the metal to enter quickly into other mould cavities.

Choke:

Also called sprue base well.

→ Choke is that part of the gating system which has the smallest cross-sectional area and helps in controlling the rate of metal flow, thus ensuring lower metal flow velocity in runners and minimizing sand erosion in runners.

A pressure die casting setup was tested by injecting water (density 1000 kg/m3) at a pressure of 200 bar. Mould-filling time was found to be 0.05 s. Afterwards, the actual casting is made by injecting the liquid metal (density 2000 kg/m3) at an injection pressure of 400 bar. Neglect all losses (friction, viscous-effect, etc.). The approximate mould-filling time (in s) is:

  1. 0.05
  2. 0.075
  3. 0.1
  4. 0.2

Answer (Detailed Solution Below)

Option 1 : 0.05

Design of Gating System Question 7 Detailed Solution

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Concept:

The mould filling time is given by:

t=Volume of castingVolume flow rate=VA×2gh

Now, h is the pressure head and can be written as h = P/ρg 

Thus:

t =VA×2gh=VρA×2Pt ρP

Calculation:

Given:

ρ1 = 1000 kg/m3, ρ2 = 2000 kg/m3, P1 = 200 bar, P2 = 400 bar, t1 = 0.05 sec, t2 = ?

t2t1=ρ2P2×P1ρ1=20001000×200400=1

Thus t2 = t1 = 0.05 s

Chillers are used in casting to ______. 

  1. enable smooth flow of metal inside the cavity 
  2. provide support to mould cavity 
  3. aid smooth removal of the core 
  4. enhance cooling rates of molten metal 

Answer (Detailed Solution Below)

Option 4 : enhance cooling rates of molten metal 

Design of Gating System Question 8 Detailed Solution

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Explanation:

Chills:

Chills and padding are used to provide uni-directional solidification.

Chills are metallic objects, which are placed in the mould to increase the cooling rate of castings. Tapering of thinner section towards thicker section is known as 'padding'. This will require extra material. If padding is not provided, centre line shrinkage or porosity will result in the thinner section.

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Core: 

  • Cores are used to get the internal cavity in the castings.
  • Cores are placed into the mould after the removal of the casting. These are made up of sand are used in permanent moulds also.
  • The cores are surrounded by molten metal and therefore subjected to severe thermal and mechanical conditions.
  • Core sand should be of higher strength than the moulding sand.

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Core prints: 

  • Core prints are the projections on the pattern and recess inside the mould cavity to position the core properly.
  • As we know the density of core (made of sand) is less than the density of metal being poured in the cavity.
  • So there will be an upward buoyancy force on the core.
  • To overcome this defect the core prints are used.
  • This force and hence core print design will depend on the moulding sand characteristics.

Chaplets: 

  • Chaplets are used to support the core inside the mould cavity. 
  • Chaplet also takes care of its own weight and overcomes the metallostatic forces.

A schematic diagram of the poring basin and the sprue of a gating system is shown in the figure. The depth of molten metal in the pouring basin is 100 mm and the height of the sprue is 1,500 mm.

Sprue

Considering the cross-section of the sprue is circular, the ratio d1:d2 to avoid aspiration is

  1. 3 : 2
  2. 5 : 6
  3. 15 : 16
  4. 1 : 2

Answer (Detailed Solution Below)

Option 4 : 1 : 2

Design of Gating System Question 9 Detailed Solution

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Concept:

To avoid aspiration effect

A1A2=V2V1=R=hthsht

where ht = = Total height = h+ hb, h= sprue height, hb = basin height

Calculation:

Given:

Sprue

h2 = 1500 mm, hb = 100 mm

total height, ht =  1500 + 100 = 1600 mm

we know that

A1A2=V2V1=R=hthsht

(d1d2)2=160015001600=1001600=1040

∴ d1: d2 = 1 : 2

A cylinder of 150 mm diameter & 200 mm height is to be cast without any riser. The cylinder is moulded entirely in drag of a green sand flask & is top gated. The cope of flask is 200 mm height & the height of metal pouring is 50 mm above the cope. A tapered sprue is employed & the gating ratio is 1 : 1.5 : 2. The time taken _________ (in seconds) to fill the casting cavity neglecting energy losses, if the ingate area is 400 sq-mm.

Answer (Detailed Solution Below) 7.7 - 8.1

Design of Gating System Question 10 Detailed Solution

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In top gating system:

tf=Mouldvolume(Vm)Moltenmetalflowrate(AcVc)

D167

As gating ratio is given:

Achoke : Arunner : Aingate = 1 : 1.5 : 2

Given Aingate = 400 sq-mm.

Thus, Achoke=4002=200sqmm

Choke area will be considered for molten metal flow rate because choke regulates the rate of pouring of molten metal.

Vc=2ght=2×9810×250

= 2214.7234 mm/s

tf=π4d2h200×2214.7234=π4×1502×200200×2214.7234=7.979sec

While cooling, a cubical casting of side 40 mm undergoes 3%, 4% and 5% volume shrinkage during the liquid state, phase transition and solid state, respectively. The volume of metal compensated from the riser is

  1. 2%
  2. 7%
  3. 8%
  4. 9%

Answer (Detailed Solution Below)

Option 2 : 7%

Design of Gating System Question 11 Detailed Solution

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Explanation:

The volume of metal compensated by rises does not constitute cooling during the solid state. Riser can compensate for volume shrinkage only in liquid stage and transition stage.

∴ Volume compensated by riser = liquid shrinkage + phase transition shrinkage = 3 + 4 = 7%

Which of the following components feed(s) molten metal to casting set-up? 

  1. Ladle
  2. Dowel pins
  3. Riser
  4. Core

Answer (Detailed Solution Below)

Option 1 : Ladle

Design of Gating System Question 12 Detailed Solution

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Explanation:

Ladle:

  • Ladle is used to feed molten metal to casting set-up.
  • Types of ladles:

Hand Ladle:

  • It is a bucket with removable, lever arm and handle shank. It is used when the quantity of molten metal is small. It can be carried by a single person. Its carrying capacity varies from 10 to 20 kg.

Shank or Bull Ladle:

  • A shank or bull ladle is carried by two persons and used for medium capacity of molten metal. Its carrying capacity varies from 30 to 150 kg.

Tea Pot Ladle:

  • Tea pot ladle is used for small and medium-sized mould. Tea pot ladle allows the molten metal to be taken out from the bottom opening provided. The bottom opening is advantageous as it does not disturb the slag floats on top.

Bottom-Poured Ladle:

  • Bottom poured ladle is used for top-run or direct-pour into the mould. The molten metal is poured through the bottom hole, which is operated by a graphite stopper and lever. Slag, being lighter, floats at the top of the molten metal and pure metal is poured into the mould. Therefore, it is also known as self-cleaning ladle.

Monorail or Trolley Ladle:

  • The molten metal is carried in a trolley. The trolley is mounted on the mono­rail for easy movement to the pouring site. The molten metal is poured through a lever provided with crucible. A hand wheel is also provided for raising and lowering the crucible

F1 Madhuri Engineering 04.07.2022 D12

In a gating system design, a down sprue of 180 mm length has a diameter of 20 mm at its top end. The liquid metal in the pouring cup is maintained up to 60 mm height. The diameter (in mm) of the down sprue at its lower end to avoid aspiration will be:

  1. 11.11
  2. 14.14
  3. 25
  4. 17.32

Answer (Detailed Solution Below)

Option 2 : 14.14

Design of Gating System Question 13 Detailed Solution

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Concept:

F1 Ashik Madhu 04.09.20 D4

 

To avoid aspiration in a gating system, the diameter of the downsprue at its bottom should be calculated based on Bernoulli’s equation and the principle of continuity. The flow of molten metal must be such that the pressure at the bottom of the sprue remains atmospheric to prevent air entrainment.

Calculation: 

Given:

Length of downsprue = 180 mm, Diameter at top = 20 mm, Height of liquid metal in pouring cup = 60 mm

Total head (H) = 180 + 60 = 240 mm = 0.24 m

Using Bernoulli’s equation:

v=2gH=2×9.81×0.24=4.70882.17 m/s

Assuming atmospheric pressure at both ends and negligible velocity at the top due to larger cross-section area:

Apply continuity equation: A2v2=A3v3

Let D2 = 20 mm, and assume v2 negligible, then use ratio of areas:

D3=D2×v2v3=20×1.0852.17=20×0.5=20×0.70714.14 mm

 

A gating ratio is a:b:c. What does ‘a’ signifies? 

  1. Runner area
  2. Pouring basin area
  3. Sprue area
  4. Number of gates

Answer (Detailed Solution Below)

Option 3 : Sprue area

Design of Gating System Question 14 Detailed Solution

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Explanation:

Gating ratio:

The term gating ratio is used to describe the relative cross-sectional areas of the components of gating system.

It is defined as the ratio of the sprue area (As) to the total runner area (Ar) to the total gate area (Ag).

i.e. Gating ratio a : b : c = Sprue area : Runner area : Gate area.

Gating ratio is grouped in two classes i.e. pressurised and unpressurised gating system.

Additional Information

Pressurised gating system:

  • The proportion of sprue, runner and gate area are so arranged that back-pressure is maintained in the gating system.
  • This requires that the total gate area is not greater than the area of the sprue. Eg. 1 : 0.75 : 0.5, 1 : 2 : 12 : 1 : 1.
  • A pressurised gating system keeps itself full of metal.
  • Air aspiration is minimised.
  • Smaller loss of metal and greater yield.
  • High metal velocities may cause turbulence at the junctions and corners in mould cavity.
  • Method suitable for ferrous material and brass

Un-pressurised gating system:

  • The unpressurised gating system produces lower metal velocities and permits greater flow rates. 
  • Requires careful design to ensure complete filling, and large-sized runners and gates, which reduce the yield and increase the wastage of metal.
  • this system is generally adopted for metal such as Aluminium and Magnesium. The ratio used are 1 : 2 : 2, 1 : 3 : 3.

A sand casting mould assembly is show in the given figure. The element marked A and B are

F1 Vishamber Ravi 04.05.21 D13

  1. Sprue and riser
  2. Ingate and riser
  3. Drag and runner
  4. Riser and runner

Answer (Detailed Solution Below)

Option 4 : Riser and runner

Design of Gating System Question 15 Detailed Solution

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Explanation:

Gating System: 

  • It refers to the channels through which the molten metal flows to the die cavity.
  • Its key objective is to ensure its smooth and complete flow from the ladle to the mould cavity.
  • To achieve perfect castings, it is important to have a gating system that is well designed.

Important elements related to the Gating system are:

Cope: Top half of the mould.

Drag: Bottom part of the mould

Mould Cavity: Gap created in mould using pattern

Pouring Cup: From here metal is poured

Sprue: Pipe shaped. From the pouring basin, the metal flows into the sprue.

Runner: The horizontal hollow channels that connect the bottom of the sprue to the mould cavity.

Ingate: The region where runner joins with the cavity

Riser: Excess metal poured into the mould flows into these cavities. They act as reservoirs, as the metal solidifies inside the cavity, it shrinks, and the extra metal from the riser flows back down to avoid holes.

Hence, A and B in question are Riser and Runner respectively.

Additional Information

Gating ratio =  a : b : c

Where, a = cross-sectional area of sprue; b = total cross-sectional area of runner;  c = cross-sectional area of ingates.

Pressurized gating system

Unpressurized gating system

The gating ratio may be of the order of 3:2:1

The gating ratio may be of the order of 1:3:2

Air aspiration effect is minimum.

Air aspiration effect is minimum

The volume flow of liquid from every ingate is almost equal.

The volume flow of liquid from every ingate is different

Smaller in volume for a given flow rate of the metal. 

Larger in volume for a given flow rate of the metal. 

As velocity is high, severe turbulence may occur at corners.

As velocity is low, turbulence is reduced.

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