Physics is studied by science students and is concerned with the nature and properties of matter and energy. Physics topics include mechanics, heat, light and radiation, sound, electricity, magnetism, and the structure of atoms.
Study the following Physics past questions and answers for JAMB, WAEC, NECO and Post UTME. Prepare yourself with official past questions and answers for your upcoming examinations.
B) cancel the effect of the earth's magnetic field
C) protect the magnet from stray electric field
D) increase the strangth of the magnets
Exam Body: West African Examinations Council (WAEC)
Explanation:
A magnet keeper, also known historically as an armature, is a paramagnetic bar made from soft iron or steel, which is placed across the poles of a permanent magnet to help preserve the strength of the magnet by completing the magnetic circuit.
A \(10\mu \mathrm{C}\) charge moves with a velocity of \(1.0 \times 10^5 ms^{-1}\) at right angle to a uniform magnetic field of flux density \(5.0 \times 10^{-4}T.\) Calculate the force on the charge.
Options
A) \(5.0 \times 10^{-5} \mathrm{N}\)
B) \(5.0 \times 10^{-4} \mathrm{N}\)
C) \(5.0 \times 10^5 \mathrm{N}\)
D) \(5.0 \times 10^6 \mathrm{N}\)
Exam Body: West African Examinations Council (WAEC)
A) number of holes are equal to the number of electrons
B) electrical resistivity increases
C) electrons are the majority charge carriers
D) holes are the majority charge carriers
Exam Body: West African Examinations Council (WAEC)
Explanation:
In p-type semiconductors, holes are the majority carriers and electrons are the minority carriers. P-type semiconductors are created by doping an intrinsic semiconductor with acceptor impurities. A common p-type dopant for silicon is boron or gallium.
Let Δx be the uncertainty in the measurements of position and Δp the uncertainty in measurement of momentum. The uncertainty principle relation is given as
Options
A) Δx . Δp = h
B) Δx . Δp ≤ h
C) Δx . Δp ≥h
D) Δx . Δp > h
Exam Body: West African Examinations Council (WAEC)
Explanation:
Uncertainty principle, also called Heisenberg uncertainty principle or indeterminacy principle, statement, articulated (1927) by the German physicist Werner Heisenberg, that the position and the velocity of an object cannot both be measured exactly, at the same time, even in theory. The very concepts of exact position and exact velocity together, in fact, have no meaning in nature.
Two objects of masses 80kg and 50kg are separated by a distance of 0.2m. If the gravitational constant is 6.6 x 10-11Nm kg, calculate the gravitational attraction between them.
Options
A) 4.9 × 10-9N
B) 1.3 × 10-6N
C) 6.6 × 10-8N
D) 6.6 × 10-6N
E) 2.6 × 10-9N
Exam Body: West African Examinations Council (WAEC)
