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

Question 16 :

Which of the following is not essential for the productipn of elèctron by thermionic emission?

A. Tungsten target
B. Reflection plate
c) Futrescent
C. Hot cathode

Question 17 :

If an object moves with a constant speed round a circlf, it has an acceleration which is

A. Constant in magnitude and varying \(z\) cheation
B. Varying in magnitude and constant in pirection
C. Constant in magnitude andidireevion
D. Varying in magnitude and direction

Question 18 :

An electric string of length \(X\) is stretched through a length by force F. The area of cross-section of the string is \(A\) and its young modulus is \(E\).
Which of the following expression is correct?

A. \(F =\frac{E A c}{x}\)
B. \(F =\frac{E A e}{X^{2}}\)
C. \(F =\frac{E A \varepsilon^{2}}{x}\)
D. \(F =\frac{E A e^{2}}{X^{2}}\)

Question 19 :

The density of a solid is \(130 gcm 3\) at the temperature of \(25^{\circ} C\). Find the density at \(150^{\circ} C\) the linear expansion of the solid is \(2.0 \times 105 K 1\).

A. \(21.90 gcm 3\)
B. \(9.021 .90 gcm 3\)
C. \(12.9 gcm 3\)
D. \(20.521 .90 gcm 3\)

Question 20 :

A bullet leaves the barrel of a gun with a speed of \(80 ms\). If the barrel is 20 theng. Lindthe acceleration of the bullet.

A. \(160 ms ^{\prime}\)
B. 40ms'
C. \(800 ms ^{\prime}\)
D. \(1600 ms 1\)