Obafemi Awolowo University Physics Post Utme Past Questions and Answers

Question 21 :

The principle of operation of an induction coil is based on ____________

A. Ohm's law
B. Ampere's law
C. Faraday's law
D. Coulomb's law

Question 22 :

The equation
\({ }_{62}^{150} X \rightarrow{ }_{63}^{150} Y+k+\) energy
represents

A. \(\alpha\) - decay
B. \(\beta\) - decay
C. \(\gamma\)-decay
D. Photon emission

Question 23 :

Which of the following radiations cannot be deflected by an electric field or magnetic field?
(i) \(\alpha\) - rays (ii) \(\beta\) - rays (iii) \(\gamma\) - rays (iv) \(x\)-rays

A. (i) and (ii) only
B. (i) and (ii) only
C. (iii) and (iv) only
D. (i) and (iii) only

Question 24 :

The half - life of a radioactive element is 9 days. What fraction of atoms has decayed in 36 days?

A. \(1 / 16\)
B. \(1 / 4\)
C. \(1 / 2\)
D. \(15 / 16\)