Physics JAMB, WAEC, NECO AND NABTEB Official Past Questions

You are provided with a potentiometer XY, a voltmeter, V, a standard resistor R, an accumulator, E a plug key, K, a jockey, and connecting wires.

1.  Connect a circuit as shown in the diagram above.
2. Close the key and use the jockey to make contact with the potentiometer with XY at a point N such that l = XN= 15cm.
3. Read and record the value of the potential difference V on the voltmeter.
4. Evaluate l\(^{-1}\) and V\(^{-1}\).
5. Repeat the procedure for five other values of I= 25, 35, 45, 55, and 65cm respectively. Read and record the value of V and evaluate V\(^{-1}\) and l\(^{-1}\) in each case. Tabulate your readings.
6. Plot a graph V\(^{-1}\) on the vertical axis against l\(^{-1}\)on the horizontal axis starting both axes from the origin (0,0).
7. Determine the slope, s, of the graph.
8. Evaluate k = \(\frac{1}{s}\)
9. State two precautions taken to ensure accurate re- results.

(b)i. State four factors on which the resistance of a wire depends.

ii. A resistance Wire of length 100cm is connected in a circuit. If the resistance per unit length of the wire is 0.02 \(\Omega\)cm\(^{-1}\), how much heat would be produced in the wire if a voltmeter connected across its ends indicates 1.5V while the current runs for 1 minute?

using the diagram above as a guide:

1. Trace the outline ABC of the equilateral triangular glass prism provided.
2. Remove the prism. Draw a line MN such that it makes an angle i = 5° with the normal at N on side AB of the outline.
3. Fix two pins at P\(_{1}\) and P\(_{2}\) on MN. Replace the prism on its outline.
4. Looking through the face BC of the prism, fix one pin at P\(_{3}\) and another at P\(_{4}\) Such that they are in a straight line with the images of the pins at P\(_{1}\) and P\(_{2}\).
5. Remove the prism and the pins. Draw a line to join P\(_{4}\) and P\(_{3}\). Produce line P\(_{4}\)P\(_{3}\) to meet the line BC of the outline at CQ and line MN produced at P.
6. Draw a normal to BC at Q. Measure and record the angles \(\theta\) and e. Evaluate \(\phi\) = i + e.
7. Repeat the procedure, using a different outline in each case, for four other values of i = 100, 159, 20, and 25 respectively. Evaluate \(\phi\) =i + e in each case. Tabulate your readings.
8. Plot a graph of \(\theta\) on the vertical axis against \(\phi\) on the horizontal axis starting both axes from the origin (0,0).
9. Determine the slope of the graph and the intercept on the vertical axis.
10. State two precautions taken to ensure accurate results.

(b)i. Explain what is meant by the statement: the refractive index of glass is 1.5. 

ii. Calculate the critical angle of a medium of refractive index 1.65 when light passes from the medium to air.

You have been provided with a retort stand, clamp and boss, a set of masses, a spiral spring, stopwatch, split cork, and other necessary apparatus. Using the diagram above as a guide, carry out the following instructions;

1. Suspend the spiral spring vertically as shown in the diagram.
2. Suspend a mass hanger on the free end of the spiral spring and add a mass, m 50.0g to the hanger.
3. Pull the hanger gently downwards and release to set it into vertical 0scillations.
4. Determine the time, t, for 20 complete oscillations.
5. Evaluate the period, t, of the oscillation. Also, evaluate T\(^{2}\).
6. Repeat the procedure for four other values of m= 70, 90, 110, and 130g. In each case, determine t and evaluate T and T\(^{2}\). Tabulate your readings.
7. Plot a graph of T\(^{2}\) on the vertical axis against m on the horizontal axis.
8. Determine the slope, s, of the graph and the intercept, l, on the vertical axis.
9. Evaluate k = 4\(\frac{\pi ^{2}}{s}\), Take t = \(\frac{22}{7}\)
10. State two precautions taken to ensure accurate results.

(b)i. Define Young modulus and force constant.

ii. A force of magnitude 500N is applied to the free end of a spiral spring of force constant 1.0 x 10\(^{4}\) Nm\(^{-1}\). Calculate the energy stored in the stretched spring.

(a) State two;

(i) differences between nuclear fusion and nuclear fission;

(ii) peaceful uses of atomic energy 

(b)(i) Explain chain reaction

(ii) State (I) one condition necessary for chain reaction to occur. 

(II) two components in a nuclear reactor used to control chain reaction.

(c)(i) A nuclear reaction is given \(^2_1H + ^3_1H = ^4_0n\)  + energy

What type of nuclear reaction is it?

(ii) The isotope of a nuclide has a half life of 5.40 x 10\(^3\) s, Calculate its decay constant.

Explain wave-particle paradox

(a) (i) Explain (I) electric potential; (II) electric potential energy

(ii) State the SI unit of each of the term in (a)(i) above

(b) An isolated electrically charged sphere of radius, r, and charge, Q, is supported on an insulator in air of permitivity, \(\varepsilon_o\). Write down;

(i) an expression for the electric field intensity on the surface of the sphere;

(ii) an expression for the electric potential at the surface of the sphere;

(iii) a relationship between the electric field intensity and the electric potential at the surface of the sphere

(c) The plates of a parallel plate capacitor, 5.0 x 10\(^{-3}\) m apart are maintained at a potential difference of 5.0 x 10\(^{4}\) V. Calculate the magnitude f the

(i) electric field intensity between the plates

(ii) force on the electron

(iii) acceleration of the elctron

[electronic charge = 1.60 x 10\(^{-19}\)C, mass of electron = 9.1 \times 10\(^{-31}\) kg]

(a) Explain (i) refraction of a wave;

(ii) critical angle

(b) State two conditions necessary for (i) total internal reflection of a wave to occur

(ii) interference wave patterns to be formed

(c) The distance between two successive crests of a water wave travelling at 3.6ms\(^{-1}\) is 0.45m, calculate the frequency of the wave

(d) A ray of light is incident at an angle of 30° at an air-glass interface.

(i) Draw a ray diagram to show the deviation of the ray in the glass.

(ii) Determine the angle of deviation. [Refractive index of glass = 1.50]

(a) Explain specific latent heat

(b)(i) Describe how the specific latent heat of fusion of ice can be determined by the method of mixtures.

(ii) State two precautions to be taken to ensure accurate results.

(c) Steam, at 100°C, is passed into a container of negligible heat capacity containing 20 g of ice and 100 g of water at 0°C, until the ice is completely melted. Determine the total mass of water in the container.  [Specific latent heat of steam = 2.3 x 10\(^3\) Jg\(^{-1}\), specific latent heat of ice = 3.4 x 10\(^{2}\) Jg\(^{-1}\), specifit heat capacity of water = 4.2 Jg\(^{-1}\) K\(^{-1}\)]

(a) Sketch a diagram of a simple pendulum performing simple harmonic motion and indicate positions of maximum potential energy and kinetic energy.

(b) A body moving with simple harmonic motion in a straight line has velocity, v and acceleration, a, when the instantaneous displacement, x in cm, from its maximum position is given by x = 2.5 sin 0.4 \(\pi t\), where t is in seconds. Determine the magnitude of the maximum (i) veloxity; (ii) acceleration

(c) A mass m attached to a light spiral is caused to perform simple harmonic motion of frequency

f = \(\frac{1}{2 \pi} \sqrt{\frac{k}{m}}\), where k is the force constant of the spring.

(i) Explain the physical significance of \(\sqrt{\frac{k}{m}}\).

(ii) If m = 0.30 kg, k = 30Nm\(^{-1}\) and the maximum position is 0.015m, calculate the maximum;

(i) kinetic energy

(ii) tension in the spring during the motion [g = 10 ms\(^{-1}\), \(\pi\) = 3.142]

Using the kinetic theory of matter, explain the definite structure of solids.

(a) Define surface tension

(b) State two methods by which the surface tension of a liquid can be reduced

(a) Define elastic limit

(b) State Hookes laws of elasticity

(a) Define Young modulus of elasticity;

(b) A spiral spring extends from a length of 10.0 cm to 10.01 cm when a force of 20 N is applied on it. Calculate the force constant of the spring.

State (a) the principle upon which the lightening in fluorescent tubes operate;

(b) two factors on which the colour of light from a fluorescent tube depends.

(a) Explain cations (b) Draw and label an electrolytic cell.

 Describe, with the aid of a diagram, how a wave can be plane polarized.

 A ball is projected specific latent heat of ice = 3.4 x 10\(^{2}\) Jg\(^{-1}\) horizontally from a height of 20m above the ground specific heat capacity of water = 4.2 Jg\(^{-1}\) K\(^{-1}\) with an initial velocity of 0.4ms\(^{-1}\). Calculate the horizontal distance moved by the ball before hitting the ground. [g = 10ms\(^{-1}\)]

A stone thrown horizontally from the top of a vertical ice is completely melted. Determine the total mass of wall with a velocity of 15ms\(^{-1}\), hits the horizontal ground water in the container at a point 45m from the base of the wall. Calculate the specific latent heat of steam = 2.3 x 10\(^3\) Jg\(^{-1}\) height of the wall. [g = 10ms\(^{-2}\)]

Uranium of atom number 92 and mass number 238 emits an alpha particle from its nucleus. The new nucleus formed has respectively, atomic number and mass number

The mass of a proton is 1.0089\(\mu\) and that of a neutron is 1.0089\(\mu\). Determine the energy evolved in stabilizing the nucleus of nitrogen of mass number 14 with 7 protons and 7 neutrons. [speed of light = 3.0 x 10⁸ms^-1; 1\(\mu\) = 1.67 x 10^-27kg]

Light of energy 5.0 eV falls on a metal of work function 3.0 eV and electrons are emitted, determine the stopping potential. [electronic charge, e = 1.60 x 10⁸ms^-19]