MECHANICAL ENGINEERING MCQ SECTION 29

281. Maximum flame temperature in case of gas welding occurs at

(A) at the tip of the fame

(B) at the tip of the torch

(C) inner cone

(D) next to the inner cone

Answer: - next to the inner cone

282. Preheating before welding is done to

(A) make steel softer

(B) burn away oil, grease etc. from work surface

(C) prevent cold cracks

(D) prevent workpiece deformation

Answer: - prevent cold cracks

283. Crater wear starts at some distance from the tool tip because

(A) Cutting fluid cannot penetrate that region

(B) stress on rake face is maximum at the region

(C) tool strength is minimum at that region

(D) tool temperature is maximum at that region

Answer: - tool temperature is maximum at that region

284. Back rack angle

(A) Appears at the second position of tool signature

(B) Appears at the start of tool signature

(C) Appears at the middle of tool signature

(D) Appears at the end of tool signature

Answer: - Appears at the start of tool signature

285. Tachometers are used for measurement of

(A) Displacement

(B) angular velocity

(C) vibration

(D) time

Answer: - angular velocity

286. The correct sequence of the centrifugal pump components through which

the fluid flows is

(A) Impeller, Suction Pipe, Foot Valve and Strainer, Delivery Pipe.

(B) Foot Valve and strainer, Suction Pipe, Impeller, Delivery Pipe

(C) Impeller, Suction Pipe, Delivery Pipe, Foot Valve Strainer

(D) Suction Pipe, Delivery Pipe, Impeller, Foot Valve and Strainer

Answer: -Foot Valve and strainer, Suction Pipe, Impeller, Delivery Pipe

287. The stress requried to casuse slip in a metal single crystal depends upon

(A) Crystal Structure

(B) Temperature

(C) Orientation of the crystal with respect to the applied stress

(D) Cross-sectional area

Answer: -Orientation of the crystal with respect to the applied stress

288. A material whose molecular properties allow considerable reversible extension

is referred to as

(A) A polymer

(B) A Plastic

(C) A elastomer

(D) An isomer

Answer: -A elastomer

289. Joul-Thomson coefficient for an ideal gas having equation Pv = RT is

(A) Unity

(B) Infinite

(C) 0.5

(D) Zero

Answer: -Zero

290. In steam tables, the entropy is shown as zero for

(A) Saturated vapour at atmospheric pressure

(B) Saturated liquid at atmospheric pressure

(C) Saturated vapour at 0°C

(D) Saturated liquid at 0°C

Answer: -Saturated liquid at 0°C