One shot Marathon Series II Casting ,Welding & Metal Forming for ESE & GATE ME Exams

Question 1

Wavy edges is a defect of_____.

Question 2

An aluminium alloy (density 2600 kg/ $Description: D:\GradeStack Courses\GATE Tests (Sent by Ravi)\GATE-ME-2014-Set-1_files\image185.png$ ) casting is to be produced. A cylindrical hole of 100 mm diameter and 100 mm length is made in the casting using sand core (density 1600 kg/ $Description: D:\GradeStack Courses\GATE Tests (Sent by Ravi)\GATE-ME-2014-Set-1_files\image185.png$ ). The net buoyancy force (in newton) acting on the core is_______.

Question 3

A downsprue of length 180mm has a diameter of 20 mm at the top end. The liquid metal in the pouring cup is maintained upto a height of 60mm. The theoretical diameter of the sprue at the lower end to ensure no aspiration effect is _________ mm

Question 4

The core in the centrifugal casting is made of ________.

Question 5

Projection welding is ____.

Question 6

Out of the given process parameters below,which one of the following is not relevant to ultrasonic welding __________?

Question 7

Sand acquires a predetermined shape under pressure and retains the same when pressure is removed. This is due to the property of sand known as:

Question 8

The DC power source for arc welding has the characterstic equation 4V + I = 280, where V= voltage and I= current in amp. For maximum arc power at the electrode, current should be set at _____________ amp.

Question 9Multiple Correct Options

Which of the following statement is/are correct regarding Atomic hydrogen welding?

Question 10

Which of the following statement is correct for the “Autogenous joint” _________?

Question 11

A loose piece pattern is used for ________.

Question 12

A strip having thickness 30 mm is to be rolled to a thickness of 15 mm using rolls mills of diameter 300 mm. For unaided bite, the coefficient of friction should be nearly :

Question 13

A standard cylindrical specimen ( h=5.08 cm) is used for measuring the permeability number of molding sand. 2000 cubic centimetre air is allowed to pass through the specimen for 2.5 minutes. The manometer indicates pressure as 3 g/cm².The permeability number of molding sand will be _________.

Question 14

A material is being wire drawn , the power law behavior for which is expressed as σ=50ε^0.3. The maximum strain in the material per pass in an annealed condition, correct to two decimal places is ___________.(Assume no friction and back pull.)

Question 15Multiple Correct Options

A weld is made using the MIG welding process with the following parameters: current I = 250A, Voltage = 40V, welding speed of 1.54 cm/min, wire diameter of 1.40 mm, wire feed rate: 500 mm/min. The workpiece and filler are of titanium for which the specific energy is 200 J/mm³. Assuming a thermal efficiency of welding process 64% choose the correct one ___________.

Question 16

The cross section of the conductor is reducing in the direction of current in welding process.The direction of electromagnetic force on droplet of metal is ____.

Question 17

The percentage change in the solidification time of a casting of cuboid shape when each dimension is increased to 3 times is __________. (Assume conditions remain same)

Question 18

Due to cold forming, ductility of a material_____.

Question 19

A 4 mm thick steel sheet of 25 mm width is to bent at an angle of 60

having a bend radius of 5 mm. The bend allowance for this operation will be __________ mm( Given bend constant k= 0.33)

Question 20

A 10 mm diameter annealed steel wire is drawn through a die at a speed of 0.5 m/s to reduce the diameter by 20%. The mean flow stress is 357 MPa. The power required for drawing process is _________ (kW).

Question 21

For a sand casting process, the following data is known :

and exponent in the Chvorinov’s equation as It is desired to double the solidification time for a given unit volume of the material. The magnitude of percentage reduction in surface area of the casting required will be __________.

Question 22Multiple Correct Options

Consider the following voltage length characteristic of a DC arc: V = (40 + 70 L) volts, where L is the length of arc in cm. If the power source is approximated by a straight line with an open circuit voltage = 100V and a short circuit current equal to 1200 A, then __________.

Question 23

A casting block is produced using sand moulding. Pattern making allowance is 2%. Calculate the ratio of volume of pattern to the volume of casting upto two places of decimal, if casting block material is grey cast iron with dimensions 500×200×10 mm.

Question 24

In the rolling process, the roll separating force can be decreased by __________.

Question 25

A casting of size 250 cm × 250cm × 30 cm was filled by bottom gate. Total height of pouring basin and Sprue is to be 50 cm. Calculate the time to fill the casting. The area of gate is 15 cm²_________ (in min).