517. With increase in temperature, the electrical conductivity of a __________ decreases.
A. Semi-conductor
B. Metal or alloy
C. Dielectric
D. None of these
✅ The correct answer is option A.
520. Basic open hearth furnace (BOF) is not used for producing __________ steel.
A. Killed
B. Rimming
C. High alloy
D. None of these
✅ The correct answer is option C.
522. Sacrificial anode method is used in the protection of pipelines which are buried underground. Sacrificial anode
A. Occurs higher in the electro-chemical series of metals
B. Is exemplified by magnesium plate
C. Is much cheaper than the cathodic base material to be guarded against corrosion
D. All of the above
✅ The correct answer is option D.
524. Light year is the unit of
A. Distance
B. Time
C. Intensity of light
D. None of these
✅ The correct answer is option A.
526. Induced draft fans provided in large thermal power plant boilers have __________ blades.
A. Forward curved
B. Backward curved
C. Double curved
D. Radial or straight
✅ The correct answer is option B.
528. Ferromagnetic material owe their properties to __________ inner sub-shells.
A. Completely filled
B. Partially filled
C. Equally filled
D. Vacant
✅ The correct answer is option B.
530. Direct conversion of thermal energy to electrical energy is facilitated by the
A. Fuel cells
B. Photo voltaic cell
C. Magneto hydrodynamic generator
D. None of these
✅ The correct answer is option C.
532. Which of the following relationships is correct for relating the three elastic constants of an isotropic elastic material (where, E = Young’s modulus, G = Modulus of rigidity or shear modulus v = Poisson’s ratio)?
A. E = 2G (1 + v)
B. E = G (1 + v)
C. E = G (1 + v)/2
D. E = 2G (1 + 2v)
✅ The correct answer is option A.
534. At 100% relative humidity, the dew point temperature of moist air is
A. Less than the wet bulb temperature
B. More than the wet bulb temperature
C. Equal to the wet bulb temperature
D. Equal to the ambient temperature
✅ The correct answer is option B.
498. Fire on fuel oil lines can be extinguished by
A. Foam
B. Steam
C. Water
D. Carbon dioxide
✅ The correct answer is option A.