504. Unit of surface tension in S.I. unit is
A. Watt/m
B. Joule/m²
C. Newton/m²
D. Joule/m
✅ The correct answer is option B.
507. The units of the rate constant for a second order reaction are
A. Sec⁻¹. mole°
B. Moles¹. sec⁻¹
C. Moles⁻¹. sec¹
D. Moles¹. sec¹
✅ The correct answer is option C.
510. Which of the following is a commonly used manometric liquid for low pressure range?
A. Ethyl alcohol
B. Carbon tetrachloride
C. Glycerol
D. Ethylene glycol
✅ The correct answer is option B.
513. In fluid flow, and heat and mass transfer, one encounters (i) kinematic velocity (μ), (ii) molecular diffusivity (θ) and thermal diffusivity (α). The units of these quantities are.
A. μ , α and θ all have units of m/s
B. μ , α and θ all have units of m²/s
C. α and θ have units of m²/s, while μ has unit of m/s
D. α and θ have units of m/s, while μ has unit of m²/s
✅ The correct answer is option C.
516. Large diameter reinforced cement concrete (RCC) pipes are generally joined by __________ joint.
A. Flanged iron
B. Collar
C. Flexible
D. Expansion
✅ The correct answer is option B.
519. Wrought iron is never shaped by
A. Casting
B. Cold working
C. Forging
D. Welding
✅ The correct answer is option A.
521. Grey cast iron (used for making underground water pipes and manhole covers) as compared to steel has higher
A. Ductility
B. Impact strength
C. Machinability
D. Melting point
✅ The correct answer is option C.
523. Uniform ramming of sand in green sand moulding process leads to
A. Reduced chance of gas porosity
B. Greater dimensional stability of the casting
C. Uniform flow of molten metal into the mould cavity
D. Less sand expansion type of casting defect
✅ The correct answer is option B.
525. Pig iron is a product of
A. Electric arc furnace
B. Cupola
C. Blast furnace
D. Open hearth furnace
✅ The correct answer is option C.
527. Which of the following is a permanent fastening?
A. Rivets
B. Bolts
C. Screws
D. Keys
✅ The correct answer is option A.