Elementary Modern Physics - Jamb Physics Past Questions and Answers

Question 121:

• JAMB 2011

A radioactive isotope has a decay constant of 10^-5s⁴. Calculate half life

A. 6.93 x 10⁵s
B. 6.93 x 10⁵s
C. 6.93 x10⁴s
D. 6.93 x 10⁴s

Question 122:

• JAMB 2011

If the threshold frequency for tungsten is 1.3 x 10¹⁵Hz, what is its work function?
[H = 6.6 x 10^-34 Js]

A. 8.58 x 10^-19 J
B. 8.50 x 10^-15 J
C. 8.58 x 10^-17 J
D. 8.85 x 10^-18

Question 123:

• JAMB 2012

Which of the following electromagnetic waves is least energetic?

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

Question 124:

• JAMB 2012

Gamma rays are produced when

A. High velocity electrons are abruptly stopped in metals
B. Energy changes occur within the nucleus of atoms
C. Energy changes occur within the electronic structure of atoms
D. Electrons are deflected in very strong magnetic fields

Question 125:

• JAMB 2012

What is the speed of a particle of mass 10^-27kg whose wavelength is 10^-8m.
[h = 6.63 x 10^-34Js]

A. 6.63ms^-1
B. 66.30ms^-1
C. 663.00ms^-1
D. 6630.00ms^-1