Question 1

The peak wavelength of radiation emitted by a black body at a temperature of 2000 K is 1.45 μm. If the peak wavelength of emitted radiation changes to 2.90 μm, then the temperature (in K) of the black body is

Accepted Answer

1000. According to Wien's displacement law, the peak wavelength of radiation emitted by a black body is inversely proportional to its temperature. If the peak wavelength doubles from 1.45 μm to 2.90 μm, the temperature must halve from 2000 K to 1000 K.

Question 2

Feed rate in slab milling operation is equal to

Accepted Answer

product of rpm, feed per tooth and number of teeth in the cutter. The feed rate in slab milling is determined by multiplying the rotation speed (rpm) by the feed per tooth and the number of teeth on the cutter, as this accounts for the total distance the cutter moves through the material per minute.

Question 3

Metal removal in electric discharge machining takes place through

Accepted Answer

melting and vaporization. In electric discharge machining, the removal of metal occurs due to the intense heat generated by electrical discharges, which melts and vaporizes the material at the workpiece surface.

Question 4

The preferred option for holding an odd-shaped workpiece in a centre lathe is

Accepted Answer

four jaw chuck. A four jaw chuck is ideal for holding odd-shaped workpieces because it allows for independent adjustment of each jaw, providing better grip and stability for irregular shapes compared to other options.

Question 5

A local tyre distributor expects to sell approximately 9600 steel belted radial tyres next year. Annual carrying cost is Rs. 16 per tyre and ordering cost is Rs. 75. The economic order quantity of the tyres is

Accepted Answer

300. EOQ = sqrt(2*D*S/H) = sqrt(2*9600*75/16) = sqrt(90000) = 300 tyres. The stored 212 is incorrect.

Question 6

In a cam-follower, the follower rises by h as the cam rotates by δ (radians) at constant angular velocity ω (radians/s). The follower is uniformly accelerating during the first half of the rise period and is uniformly decelerating in the latter half of the rise period. Assuming that the ma

Accepted Answer

2hω/δ. The maximum velocity of the follower occurs at the midpoint of its rise, where it has accelerated uniformly to its peak speed. Given the uniform acceleration and deceleration, the relationship between the rise height, angular displacement, and angular velocity leads to the formula for maximum velocity being 2hω/δ.

Question 7

A bimetallic cylindrical bar of cross sectional area 1 m² is made by bonding Steel (Young's modulus = 210 GPa) and Aluminium (Young's modulus = 70 GPa) as shown in the figure. To maintain tensile axial strain of magnitude 10⁻⁶ in Steel bar and compressive axial strain of magnitude 10⁻⁶ in

Accepted Answer

140. The required force can be calculated using the relationship between stress, strain, and Young's modulus for both materials. Since the strains are equal in magnitude but opposite in sign, the force needed to achieve these strains in the bimetallic bar results in a total force of 140 kN.

Question 8

Air flows at the rate of 1.5 m³/s through a horizontal pipe with a gradually reducing cross-section as shown in the figure. The two cross-sections of the pipe have diameters of 400 mm and 200 mm. Take the air density as 1.2 kg/m³ and assume inviscid incompressible flow. The change in press

Accepted Answer

-1.28. The correct option is -1.28 kPa because, according to Bernoulli's principle, as the air flows from a wider section of the pipe to a narrower section, its velocity increases, resulting in a decrease in pressure. The calculations using the continuity equation and Bernoulli's equation confirm this pressure drop.

GATE Technical: M mechanical Engineering (Set 2) questions with solutions

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