Category: Physics

The bar magnet illustrated in the diagram above picks up an unmagnetized steel nail X. In turn, X picks up a similar nail Y and so on. The nails are said to be magnetized by? A. conduction B. single touch C. induction D. divided...

The diagram above shows the resultant electric field pattern due to two electric point charges P and S. Which of the following statements is correct? A. P is negatively charged while S is positively charged B. P is positively...

Nuclear fission is preferred to nuclear fusion in the generation of energy because? A. very high temperature is required for fusion B. the raw material of fusion are not easily obtained C. energy obtained from fusion is...

The minimum energy required to remove an electron from an atom is known as? A. excitation energy B. ionization energy C. binding energy D. photon energy Correct Answer: Option B B. ionization...

A radioactive element has a decay constant of 0.077s-1. Calculate its half-life? A. 12.5s B. 9.0s C. 5.1s D. 0.5s Correct Answer: Option B B. 9.0s Explanation T = 0.692/λ=0.692/0.077 =...

Which of the following statements is true of ultraviolet radiations? It A. supports the sensation of hearing B. does not cause the emission of electrons from metals C. is an electromagnetic wave D. is not capable of causing...

Which of the following statements is not true of the isotopes of an element? They A. are atoms of the same element B. have the same chemical properties C. have the same atomic number D. have the same mass number Correct Answer:...

The direction of induced current in a straight wire placed in a magnetic field is determined by using? A. Fleming’s right-hand rule B. Maxwell’s screw rule C. Faraday’s law D. Lenz’s law Correct Answer:...

Which of the following statements about an electromagnet is correct? A. it is a temporary magnet B. its strength depends on the current C. its stength depends on the number of turns in its coil D. it has permanent poles Correct...

The maximum power dissipated by a 100Ω resistor in a circuit is 4W. Calculate the voltage across the resistor. A. 10V B. 20V C. 25V D. 400V Correct Answer: Option B B. 20V Explanation V^2=PR =V =√4 ×100 =...

One difference between reactance and resistance in an alternating current circuit is? A. resistance is larger than reactance B. energy is not dissipated in a reactance C. energy is stored in a resistance but not in a reactance...

A lamp is rated 240V 60W. Calculate the resistance of its filament. A. 240Ω B. 360Ω C. 960Ω D. 1440Ω Correct Answer: Option C C. 960Ω Explanation R = V^2/P =240^2/60...