498. Which of the following nuclear reactor does not need a heat exchanger for generation of steam
A.Gas cooled
B.Liquid metal cooled
C.Pressurised water
D.Boiling water
499. The most usable isotope of uranium is
A.U233
B.U235
C.(co u240
D.(C) U238
500. The number of isotopes of hydrogen are
A.1
B.2
C.3
D.4
501. The commonly used material for shielding is
A.Lead or concrete
B.(h) lead and tin
C.Graphite or cadmium
D.Thick galvanised sheets
502. The main interest of shielding in nuclear reactor is protection against
A.X-rays
B.Infra-red rays
C.Oc,j3, and y rays
D.Neutrons and gamma rays
503. Reflector in nuclear plants is used to
A.Return the neutrons back into the core
B.ShIeld the radioactivity completely
C.Check polllution
D.Conserve energy
504. The energy required to be applied to a radioactive nucleus for the emission of a neutron is
A.1 MeV
B.2.4 MeV
C.4.3 MeV
D.7.8 MeV
Page 72 of 81