Post Utme Physics Past Questions and Answers

Question 216:

A student with a sight defect has a least distance of distinct vision of \(150 \mathrm{~cm}\). For him to read a material placed at a distance of \(25 \mathrm{~cm}\), what is the focal length of the glasses he should wear?

A. \(15.0 \mathrm{~cm}\)
B. \(17.0 \mathrm{~cm}\)
C. \(21.4 \mathrm{~cm}\)
D. \(30.0 \mathrm{~cm}\)

Question 217:

Three capacitors \(2 \mu \mathrm{F}, 3 \mu \mathrm{F}\) and \(6 \mu \mathrm{F}\) are connected in series. If the pd across the system is \(12 \mathrm{~V}\), the pd across the \(6 \mu \mathrm{F}\) capacitor is ____________

A. \(4 \mathrm{~V}\)
B. \(6 \mathrm{~V}\)
C. \(12 \mathrm{~V}\)
D. \(2 \mathrm{~V}\)

Question 218:

A current of \(0.5 \mathrm{~A}\) flows through a resistor when connected to a \(40 \mathrm{~V}\) battery. The energy dissipated in 2 minutes is ____________

A. \(1200 \mathrm{~J}\)
B. \(1500 \mathrm{~J}\)
C. \(2400 \mathrm{~J}\)
D. \(9600 \mathrm{~J}\)

Question 219:

The major difference between semiconductor and a pure metal is that ____________

A. Metals are harder than semiconductors
B. The resistance of metals decreases with temperature while the reverse is the case with semiconductors
C. The resistance of metals increases with temperature while the reverse is the case with semiconductors
D. Metals have forbidden band gaps while semiconductors do not have

Question 220:

A light of energy \(5 \mathrm{eV}\) falls on a metal and the electrons with a maximum kinetic energy of \(2 \mathrm{eV}\) are ejected. The work function of the metal is ____________

A. \(0.4 \mathrm{eV}\)
B. \(2.5 \mathrm{eV}\)
C. \(3.0 \mathrm{eV}\)
D. \(7.0 \mathrm{eV}\)