2018 - JAMB Physics Past Questions and Answers - page 6

Electric potential difference is the work needed per unit of charge to move a test charge between the two points.

Electric energy is the energy derived from electric potential energy.

In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes.

Moment = Force × Distance

= 5N x 2m

= 10Nm

Power delivered to head lamp = \(\frac{V_2}{R}\)

  = 40W

  R = \(\frac{V_2}{40}\)

  = \(\frac{(12 × 2)}{40}\)

  = 3.6Ω

X = \(\frac{4}{3}\) r = ?

  Shell’s law:. 7 = \(\frac{Sin 2^0}{ Sin r^0}\)

  \(\frac{V}{g}\) = \(\frac{Sin 30^0}{Sin r^0}\)

  Sin\(r^0\) = \(\frac{3 Sin 30^0}{4}\)

  Sin \(r^0\) = 0.375

  R \(^o\) = Sin-1 (0.375)

  R \(^o\) = 22.02 \(^o\)

  R \(^o\) = 22 \(^o\)

Power, P = 1kw=100W

  Time, t = 2mins = 2 × 60 = 120secs

  Energy = P×t

  1000 × 120 = 120,000J

  Energy = mc(θ\(_2\) – θ\(_1\))

  120,000 = 2 × 4000(θ\(_2\) – θ\(_1\))

  θ2 = 30 + 15 = 45 \(^o\) C

Ion is an atom with a net electric charge due to loss or gain of one or more electrons

Neutron is a subatomic particle of about the same mass as a proton without electric charge.

Proton is a subatomic particle with a positive charge

An impulse is a measure of the net force on the object multiplied by the time period over which this force is applied. Mathematically, impulse, F = ma.

Diffusion: the net movement of molecules/atoms from a region of high concentration to low concentration.

  Brownian motion: the erratic random movement of microscopic particles in a field.

 While diffraction is the various phenomena that occur when a wave encounters an obstacle.

Distance, d = speed × time

  = \(\frac{(\frac{100 \times 103}{3600})}{15 \times 60}\)

  = 25km