Post Utme Physics Past Questions and Answers

Question 611:

In a tuned radio receiver, \(R L C\) series circuit for resonance, the inductive and capacitive reactance \(X L\) and \(X C\) respectively are related as:

A. \(X_{L}=2 X_{C}\)
B. \(X_{L}=X_{C}\)
C. \(X_{L}=\frac{x_{c}}{2}\)
D. \(\mathrm{X}_{\mathrm{L}}=\frac{1}{\mathrm{x}_{\mathrm{c}}}\)

Question 612:

What is the energy requirement of another energy level from the energy level of \(3.7 \mathrm{eV}\), if wavelength is \(2.1 \times 10^{-7}\) \(\mathrm{m}\) ?

[take \(c=3.0 \times 10^{8} \mathrm{~m} / \mathrm{s}, 1 \mathrm{eV}=1.6\) \(\left.\times 10^{-19} \mathrm{~J}, \mathrm{~h}=6.6 \times 10^{-34} \right]\)

A. \(5 \mathrm{eV}\)
B. \(6 \mathrm{eV}\)
C. \(10 \mathrm{eV}\)
D. \(8 \mathrm{eV}\)

Question 613:

Maximum current is obtained in a series RLC circuit when the
I. total reactance is zero
II. impedance is equal to the resistance
III. capacitive reactance is equal to the inductive reactance
IV. circuit is in resonance

A. I only
B. III only
C. I and II only
D. I, II III and IV

Question 614:

A current of \(21 \mathrm{~A}\) is passed through a \(20 \mathrm{~m}\) length of two conducting wire placed \(125 \mathrm{~cm}\) apart. Determine the force of attraction between the wires assuming the current is flowing in the direction.

A. \(1.33 \times 10^{-5} \mathrm{~N}\)
B. \(4.5 \times 10^{-5} \mathrm{~N}\)
C. \(7.1 \times 10^{-5} \mathrm{~N}\)
D. \(6.4 \times 10^{-5} \mathrm{~N}\)

Question 615:

The uncertainty principle shows that any point in time the position and the momentum of a particle can be simultaneously known is ____________

A. True
B. False
C. Both particles can be measured
D. Only the momentum of the particle can be measured