Elementary Modern Physics - Jamb Physics Past Questions and Answers

Question 56:

• JAMB 1995

The half-life of a radio-active element is 9 days, what fraction of atoms has decayed in 36 days?

A. \( \frac{1}{16} \)
B. \( \frac{1}{4} \)
C. \( \frac{1}{2} \)
D. \( \frac{15}{16} \)

Question 57:

• JAMB 1997

The electromagnetic waves that are sensitive to temperature changes are

A. X-rays
B. Gamma-rays
C. Ultra-violet rays
D. Infra-red rays

Question 58:

• JAMB 1997

One of the features of the fission process is that

A. Its products are not radioactive
B. It leads to chain reaction
C. Neutrons are not released
D. The sum of the masses of the reactants equals the sum of masses of the products

Question 59:

• JAMB 1997

The graphite rods surrounding the uranium fuel rods in a nuclear reactor, are used to

A. Absorb the neutrons and hence halt the nuclear process
B. Create the neutrons and hence slow up the nuclear process
C. Slowdown the neutrons and hence slow up the nuclear process
D. Speed up the neutrons and hence speed up the nuclear process

Question 60:

• JAMB 1998

Which of the following are true about the infra-red radiation? i. it is invisible ii. it is called heat ray iii. its frequency is higher than that of blue light iv. it travels as a transverse wave

A. I, ii, iii and iv
B. I, ii, iv only
C. I, iii, iv only
D. Ii, iii, iv only