561. Why gamma rays are used to kill bacteria to sterilize surgical equipment etc ?
A. Chargeless
B. Massless
C. Highly penetrating
D. All of above

562. Beta particles ionize an atom_________________?
A. Due to the electrostatic force of attraction
B. Due to the electrostatic force of repulsion
C. Due to a direct collision
D. Due to the gravitational force

563. Alpha particles possess greater penetration power than that of beta particles due to its_____________?
A. Smaller ionization power
B. Greater ionization power
C. Neither greater nor smaller ionization power
D. Same ionization power

564. Pair production cannot take place in a vacuum as ________________?
A. Mass is not conserved
B. Energy is not conserved
C. Momentum is not conserved
D. The chargee is not conserved

565. Pair production can take place only with_________________?
A. X-rays
B. Gamma rays
C. UV-rays
D. IR-rays

566. A device for producing high-velocity nuclei is ________________?
A. Cloud chamber
B. Linear accelerator
C. A mass spectrograph
D. Wilson cloud chamber

567. Which of the following will be a better shield against gamma rays ?
A. Ordinary water
B. Heavy water
C. Lead
D. Aluminum

568. The maximum safe limit dose for persons working in a nuclear power station is ________________?
A. 1 rem per week
B. 5 rem per week
C. 4 rem per week
D. 3 rem per week

569. Radiations are used for the treatment of skin of a patient is_______________?
A. Alpha rays
B. Gamma rays
C. Beta rays
D. X-rays

570. Which branch of science plays an important role in the development of technology and engineering ?
A. Chemistry
B. Physics
C. Geology
D. Biology