Physics JAMB, WAEC, NECO AND NABTEB Official Past Questions

You are provided with a battery of e.m.f. E, a key K, a voltmeter, a standard resistor R\(_{0}\) = 2\(\Omega\), a resistance box R, and some connecting wires.

i. Measure and record the e.m.f. E of the battery.

i. Set up a circuit as shown in the diagram above with the key open.

iii. Set the resistance on the resistance box to R 22.

iv. Close the key, read and record the potential difference V on the voltmeter.

v. Evaluate V\(^{-1}\)

vi. Repeat the procedures for five other values of R = 5\(\Omega\) 10\(\Omega\),12\(\Omega\),15\(\Omega\) and 20\(\Omega\). In each case, record V and evaluate V\(^{-1}\) 

vii. Tabulate the results.

viii. Plot a graph with R on the vertical axis and V\(^{-1}\) l on the horizontal axis, starting both axes from the origin (0,0).

ix. Determine the slope, s, of the graph and the intercept c on the vertical axis.

x. Calculate \(\propto\) and \(\beta\) from the equations s = R\(_{0}\) \(\propto\) and c= – (R\(_{0}\)+B).

xi. State two precautions taken to obtain accurate results. 

You are provided with a converging lens and holder, a screen, a ray box containing an illuminated object pin, and a meter rule.(See illustration above)

i. Place the lens in its holder such that it is facing a distant object seen through a well-lit laboratory window. Move the screen to and fro until a sharp image of the distant object is formed on it. Measure the distance, f\(_{0}\), between the screen and the lens.

ii. Clamp the meter rule securely to the table. Place the illuminated object pin at the end R of the meter rule.

iii. Place the lens at a position P such that X = RP = 20cm.

iv. Move the screen to a position Q to receive a sharp image of the object. Measure the distance Y = PQ.

v. Evaluate Z = (X+Y)

vi. Repeat the procedure for five other values of x = 25cm. 3Ocm, 35cm, 40cm and 45cm. In each case, record X,Y and evaluate Z.

vii. Tabulate the results.

viii. Plot a graph with Z on the vertical axis and X on the horizontal axis. Draw a smooth curve through the points.

ix. Determine from your graph the minimum value of Z=Z\(_{0}\) and its corresponding distance

x. Evaluate W = ½ (\(\frac{Z_0}{4} + \frac{X_0}{2}\))

xi. State two precautions taken to ensure accurate results.

(b) i. Draw a ray diagram to show how a Convex lens forms an image of magnification less than one.

ii. Name two pairs of features in the human eye and a lens camera that performs similar functions.

You are provided with a stopwatch, a meter rule, a split cork, retort stand and clamp, a pendulum bob, a piece of thread, and other necessary apparatus.

i. Place the retort stand on a laboratory stool. Clamp the split cork.

ii. Suspend the pendulum bob from the split cork such that the point of support P of the bob is at height H = 100cm above the floor Q. The bob should not touch the floor and H should be kept constant throughout the experiment.

iii. Adjust the length of the thread such that the center A of the bob is at a height y= AQ= 20cm from the floor.

iv. Displace the bob such that it oscillates in a horizontal plane.

v. Take the time t for 20 complete oscillations.

vi. Determine the period T of oscillation and evaluate T

vii. Repeat the procedure for four other values of y = 30cm, 40cm, 50cm, and 60cm. In each case, determine T and T.

viii. Tabulate the results.

ix. Plot a graph of T on the vertical axis and y on the horizontal axis, starting both axes from the origin (0,0).

x. Determine the slope, s, of the graph and the intercept c on the vertical axis.

xi. If in this experiment SR= c, calculate R.

x. State two precautions taken to ensure accurate results.

(b) i. The bob of a simple pendulum is displaced a small distance from the equilibrium position and then released to perform simple harmonic motion Identify where its:
(\(\propto\)) kinetic energy is maximum
(\(\beta\)) acceleration is maximum

ii. An object of weight 120N vibrates with a period of 4.0s when hung from a spring. Calculate the force per unit length of the spring. [g= 10ms\(^{-2}\), \(\pi\)=3.142]

(a) (i) Define atomic spectra.
(ii) Differentiate between emission spectra and absorption spectra.

(b)

The diagram above illustrates an electron transition from energy level n = 3 to n = 1. Calculate the:

(i) energy of the photon

(ii) frequency of the photon

(ii) wavelength of the photon [h = 6.6 x 10\(^{-34}\)J s, c = 3.0 x 10\(^8\) ms\(^{-1}\); 1 ev = 1.6 x 10\(^{-19}\) J]

c)(i)Differentiate between soft x-rays and hard x-rays                                                                                                                                                                                       

(ii) Draw the circuit symbol for a p-n junction diode.                                                                                                                                                                                       

(iiii) Give the reason for doping a semiconductor material

The graph above illustrates the variation of temperature \(\theta\) with time (t) for a solid that is being heated. Which processes take place at segments P and Q respectively?
 

When ultraviolet light is incident on certain metallic p articles are emitted. These particles are called

Which of the following properties is not exhibited by sound waves?

Which of the following statements about a neutral atom is correct? The

The area under a velocity-time graph represents

An instrument used to measure relative humidity is the?

The nucleon and proton numbers of a neutral atom of an element are 238 and 92 respectively. Determine the number of neutrons in the atom. 

Which of the following liquids has the highest surface tension?
 

Which of the following materials does not serve as a safety device in electrical circuits? 
 

In the diagram above, the time taken to trace a wave between P and Q is?

Which of the following thermometers is used to measure the temperature of the human body?

The diagram above illustrates an object moving in a circular path at a constant speed. Which of the arrows indicates the direction of linear velocity?

Two bodies of masses 3.0 kg and 2.0 kg are separated by a distance of 50 cm. Calculate the force of attraction between them. [G = 6.67 x 10\(^{-11}\) Nm\(^2\) kg\(^2\)]

A rectangular piece of iron measuring 4 cm by 3 cm at 20\(^o\)C is heated until its temperature increases by 100 C. Calculate the new area of the metal. [Linear expansivity of iron is 1.2x 10\(^{-5}\) K\(^{-1}\)]

A ray of light traveling from a rectangular glass block of refractive index 1.5 into air strikes the block at an angle of incidence of 30. Calculate its angle of refraction.

The anomalous expansion of water occurs in the range 
 

Which property of a wave remains constant when the wave travels from one medium into another?