451. Pick up the wrong statement?
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A. Fast neutrons have energies above 1000 eV

B. Slow or thermal neutrons have energy of the order or 0.025 eV

C. Fast reactor uses moderator

D. Most serious drawback in using water as coolant in nuclear plants is its high vapour pressure

E. In a heterogeneous or solid-fuel reactor, the fuel is mixed in a regular pattern within moderator.

452. The unit of force in S.I. units is________________?
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A. dyne

B. joule

C. kilogram

D. watt

E. newton
453. According to principle of moments__________________?
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A. positive and negative couples can be balanced

B. if a system of coplanar forces is in equilibrium, then their algebraic sum is zero

C. if a system of coplanar forces is in equilibrium, then the algebraic sum of their moments about any point in their plane is zero

D. the algebraic sum of the moments of any two forces about any point is equal to moment of theiwesultant about the same point

E. none of the above

454. The unit of radio-activity is_____________?
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A. electron-volt

B. curie

C. MeV

D. electron-ampere

E. AMU

455. A projectile is fired at an angle 9 to the vertical. Its horizontal range will be maximum when 9 is_______________?
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A. 30

B. 45

C. 90.

D. 60

E. 0

456. The value of Prandtl number for air is about _______________________?
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A. 0.7

B. 10.5

C. 1.7

D. 0.3

E. 0.1

457. The thermal diffusivities for gases are generally_____________________?
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A. same as for the liquids

B. more than those for liquids

C. less than those for liquids

D. more than those for solids

E. dependent on the viscosity

458. The total emissivity power is .defined as the total amount of radiation emitted by a black body per unit_______________?
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A. thickness

B. time

C. temperature

D. area

E. area and time

459. Thermal conductivity of solid metals with rise in temperature normally___________________?
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A. remains constant

B. increases

C. decreases

D. may increase or decrease depending on temperature

E. unpredictable

460. Depending on the radiating properties, a body will be white when_________________?
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A. a = 0, x + p = 1.

B. p = 0, x = 0 and a = 1

C. p = 0, x = 1 and a = 0

D. p=l,T = 0anda = 0

E. x = 0, a + p = 1

461. The rate of energy emission from unit surface area through unit solid angle, along a normal to the surface, is known as ________________?
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A. transmissivity

B. reflectivity

C. absorptivity

D. intensity of radiation

E. emissivity

462. A fast breeder reactor uses_______________?
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A. 90% U-235

B. U-235

C. Pu-239

D. U-238

E. U-239

463. Which of the following is not the unit of energy_________________?
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A. kg m

B. kcal

C. watt hours

D. wattr

E. kg m x (m/sec)2

464. Natural uranium is made up of__________________?
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A. none of the above

B. 99.282% U238, 0.712% U235, 0.006% U234

C. 99.282% U234, 0.712% U238, 0.006% U235

D. 99.282% U235, 0.712% U238, 0.06% U234

E. 99.282% U235, 0.712% U234, 0.006% U238

465. Which of the following is expected to have highest thermal conductivity_______________?
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A. water

B. solid ice

C. steam

D. boiling water

E. melting ice

466. In vapor compression cycle, the condition of refrigerant is very wet vapor________________?
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A. before entering the compressor

B. after passing through the expansion or throttle valve

C. after passing through the condenser

D. before entering the expansion valve

E. before passing through the condenser

467. When heat is Transferred by molecular collision, it is referred to as heat transfer by __________________?
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A. scattering

B. radiation

C. conduction

D. convection and radiation

E. convection

468. In free con-vection heat transfer, Nusselt number is function of________________?
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A. Prandtl no. and Reynold no

B. Grashoff no., Prandtl no and Reynold no

C. Grashoff no. and Reynold no

D. none of the above

E. Grashoff no and Prandtl no.
469. The vapor compression refrigerator employs the following cycle_________________?
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A. Brayton

B. Rankine

C. Reversed Carnot

D. Carnot

E. Reversed Rankine

470. Forces are called coplanar when all of them acting on body lie in __________________?
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A. different planes

B. one point

C. one plane

D. different points

E. perpendicular planes

471. The boiling point of ammonia is___________________?
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A. 33.3C

B. 0C

C. -100C

D. -50C

E. 33.3C

472. Thermal conductivity of wood depends on_______________?
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A. moisture

B. temperature

C. all of the above

D. none of the above

E. density

473. In heat transfer, conductance equals conductivity (kcal/hr/sqm/C/cm) divided by ________________?
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A. C (temperature)

B. kcal (heat).

C. hr (time)

D. sqm (area)

E. cm (thickness)
474. Joule sec is the unit of_________________?
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A. universal gas constant

B. Plancks constant

C. thermal conductivity

D. kinematic viscosity

E. none of the above

475. In vapour compression cycle, the conditii of refrigerant is saturated liquid________________?
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A. before passing through the condensei

B. before entering the compressor

C. after passing through the condenser

D. after passing through the expansion throttle valve

E. before entering the expansion valve

476. Which of the following type of pump is used in liquid metal cooled reactor for circulation of liquid metal_________________?
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A. centrifugal

B. diaphragm

C. axial

D. reciprocation

E. electromagnetic
477. Plutonium is produced________________?
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A. by neutron irradiation of throium

B. in high capacity furnace

C. as basic raw material

D. artificially

E. by neutron irradiation of Uz
478. The moisture in a refrigerant is removed by___________________?
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A. safety relief valve

B. expansion valve

C. driers

D. dehumidifier

E. evaporator

479. Emissivity of a white polished body in comparison to a black body is________________?
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A. depends upon the shape of body

B. none of the above

C. lower

D. same

E. higher

480. The product of either force of couple with the arm of the couple is called_________________?
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A. moment of the couple

B. resulting couple

C. none of the above

D. resultant couple

E. moment of the forces

481. A steam pipe is to be insulated by two insulating materials put over each other . For best results__________________?
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A. better insulation should be put over pipe and better one over it

B. inferior insulation should be put over pipe and better one over it

C. both may be put in any order

D. whether to put inferior OIL over pipe or the better one would depend on steam temperature

E. unpredictable

482. If a number of forces act simultaneously on a particle, it is possible _____________________?
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A. to replace them by a single force through C.G.

B. not a replace them by a single force

C. to replace them by a couple and a force

D. to replace them by a single force

E. to replace them by a couple

483. The presence of reflector in nuclear power plants results in___________________?
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A. controlled production of neutrons

B. complete absorption of neutrons

C. decreased leakage of neutrons

D. decrease of speed of neutrons

E. increased production of neutrons

484. Two balls of same material and finish have their diameters in the ratio of 2 : 1 and both are heated to same temperature and allowed to cool by radiation. Rate of cooling by big ball as compared to smaller one will be in the ratio of____________________?
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A. 1 : 2

B. 4:01

C. 1:04

D. 1:01

E. 2:01

485. The center of gravity of a uniform lamina lies at____________________?
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A. the bottom surface

B. the mid point of its axis

C. all of the above

D. the center of heavy portion

E. none of the above

486. Cork is a good insulator because it has___________________?
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A. all of the above

B. atoms colliding frequency

C. free electrons

D. porous body

E. low density

487. A perfect black body is one which_______________?
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A. abslprbs heat radiations of all wave lengths falling on it

B. fully opaque

C. is black in colour

D. reflects all heat

E. transmits all heat radiations

488. The unit of Stefan Boltzmann constant is ____________________?
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A. watt/cm4 K

B. watt/cm2 K4

C. watt2/cm K4

D. watt/cm2 K

E. watt/cm2 K2

489. The following present serious difficulty in designing reactor shield_________________?
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A. none of the above

B. fast neutrons and gamma rays

C. alpha particles

D. thermal neutrons

E. beta particles

490. Frictional force encountered after commencement of motion is called ___________________?
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A. post friction

B. frictional resistance

C. limiting friction

D. dynamic friction

E. kinematic friction

491. A flywheel on a motor goes from rest to 1000 rpm in 6 sec. The number of revolutions made is nearly equal to___________________?
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A. 25

B. 100

C. 250

D. 50

E. 500

492. Heat flowing from one side to other depends directly on ___________________?
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A. k up the wrong case?

493. In actual machines_______________?
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A. none of the above

B. mechanical advantage is less than velocity ratio

C. mechanical advantage is greater than velocity ratio

D. mechanical advantage is equal to velocity ratio

E. mechanical advantage is unity

494. Center of gravity of a solid cone lies on the axis at the height _____________________?
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A. none of the above

B. three-eighth of the total height above the base

C. one-third of the total height above base

D. one-half of the total height above base

E. one-fourth of the total height above base
495. Metals are good conductors of heat because________________?
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A. all of the above

B. their atoms collide frequently

C. they have high density

D. their atoms-are relatively far apart

E. they contain free electrons

496. Film coefficient is defined as Inside diameter of tube________________?
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A. none of the above

B. Equivalent thickness of film

C. Film coefficient x Inside diameter Thermalconductivity

D. Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity

E. Thermal conductivity Equivalent thickness of film Specific heat x Viscocity
497. Total emissivity of polished silver compared to black body is___________________?
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A. very much lower

B. higher

C. very much higher

D. same

E. more or less same

498. Thermal conductivity of glass-wool varies from sample to sample because of variation in ________________ ?
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A. composition

B. porosity

C. all of the above

D. structure

E. density

499. Which of the following is a vector quantity___________________?
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A. speed

B. energy

C. momentum

D. mass

E. angle

500. The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body. This statement is known as_________________?
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A. Stefans law

B. Black body law

C. Krichoffs law

D. Wien law

E. Plancks law