Ladoke Akintola University of Technology Physics Post Utme Past Questions and Answers

Question 6 :

Which of the following is a mechanical wave?

A. Micro wave
B. Water wave
C. \()\)-ray
D. Infra-red ray

Question 7 :

The half-life of the radioactive substance of mass \(100 g\) is 30 minutes. What fractiods of the onginal mass is left over after \(3 hrs\) ?

A. \(3.125\)
B. \(6.25\)
C. \(1.5625\)
D. \(0.02563\)

Question 8 :

Two resistors \(12 \Omega\) and \(8 \Omega\) are connected in parallel, if the power developecin \(12 \%\), resistor is \(6 w\), determine the power developed in \(3.32\) resistor.

A. \(9 w\)
B. \(12 w\)
C. \(16 w\)
D. \(24 w\)

Question 9 :

How long will a 60 wart element take to heat water of mass \(9.5 kg\) at \(20^{\circ} C\) to \(90^{\circ} C\). Neglect heat loss (S.H. C. of water \(=4200 jkg ^{-1} K ^{-1}\) )

A. 350 secs
B. 1260 secs
C. \(2100 secs\)
D. 1500 secs

Question 10 :

The critical angle of glass is \(42^{\circ}\), the approxiffate refractive tho dex of this glass is

A. \(1.50\)
B. \(1.38\)
C. \(1.80\)
D. \(2.30\)