Question Library

An electron of mass m and charge \(\Box\) enters a uniform electric field between two metal plates P and q separated by a distance d. P is maintained at a potential V while Q is earthed. Determine an expression for the magnitude of the acceleration of electron through the field

The force experienced by a current-carrying conductor move in a magnetic field is employed in the working of the i. moving coil ammeter ii. electric bell iii. electric motor. Which of the statements above are correct?

A 500kV is applied across an X-ray tube. Calculate the maximum velocity of the electrons produced [Me = 9.1 x 10\(^{-31}\)kg, e = 1.6 x 10\(^{-19}\)C]

Fusion is not usually used for generating electric power because

(a) Explain the statement the acceleration of free fall cohesion. (b) State two factors that can affect the value of the narrow glass tube has a concave meniscus while acceleration of free fall at a place.

The diagram below represents the graph of the force applied in stretching a spiral spring against the corresponding extension produced within its elastic limit. Using the notations on the graph, determine the: (a) force constant of the spring; (b) work done in stretching the spring from 10 x 10\(^{-2}\)m to 20 x 10\(^{-2}\)m.

(a) Distinguish between the forces of adhesion and cohension (b) Give one example each of the forces of adhesion and cohesion.

Explain why water in a narrow glass tube has a concave meniscus while mecury in the same tube, has a convex meniscus

The uncertinty in determining the duration during which an electron remains in a particular energy level before returning to the ground state is 2.0 x 10\(^{-9}\)s. Calculate the uncertainty in determining its energy at that level [Take \(\frac{h}{2\pi} = h = 1.054 \times 10^{-34}\) Js]

(a) State two; (i) laws of solid friction; (ii) advantages of friction; (iii) methods of reducing friction. (b) Draw and label a diagram of a pulley system with velocity ratio of 5. (c)(i) Show that the efficiency L, force ratio M.A. and the velocity ratio V.R. of a machine are related by the equation \(E = \frac{M.A.}{V.R}\) x 100%. (ii) The efficiency of a machine is 80%. Calcuate the work done by a person using the machine to raise a load of 300 kg through a height of 4 m.[ g = 10 ms\(^{-2}\) ]

(a) Define (i) proton number; (ii) nucleon number; (iii) isotopes. (b) A nuclide \(^A_ZX\) emits \(\beta\)-particle to form a daughter nuclide Y. Write a nuclear equation to illustrate the charge conservation. (c) The radioactive nuclei \(^{210}_{84}P_o\) emits an \(\alpha\) - particle to produce \(^{206}_{82}P_b\). Calculate the energy, in MeV, released in each disintegration. Take the masses of \(^{210}_{84}P_o\) = 209.936730 u; \(^{206}_{82}P_b\) = 205.929421 u; \(^{4}_{2}He\) = 4.001504 u; and that 1u = 931 MeV

(a) State the conditions for the equilibrium of a rigid body acted upon by parallel forces. (b)(i) Describe an experiment to determine the mass of a metre rule using the principle of moments. (ii) State two precautions necessary to obtain accurate results in the experiment described in (b)(i) above. (c) A bullet of mass 120 g is fired horizontally into a fixed wooden block with a speed of 20 ms\(^{-1}\). If the bullet is brought to rest in the block in 0.1s by a constant resistance, calculate the (i) magnitude of the resistance; (ii) distance moved by the bullet in the wood.

You are provided with a constantan wire, a 2\(\Omega\) standard resistor, an accumulator E, an ammeter A, a key K, and other necessary apparatus. Measure and record the e.m.f.of the accumulator provided. Connect a circuit as shown in the diagram above. Close the key, read and record the ammeter reading \(l_o\) when the crocodile clip is not in contact with the constantan wire. Open the key. With the clip making contact with the wire, when I = 90cm, close the key. Read and record the ammeter reading /. Evaluate l\(^{-1}\). Repeat the procedure for l= 80, 70, 60 and 50cm. In each case, read and record the ammeter reading and evaluate l\(^{-1}\). Tabulate your readings. Plot a graph of l on the vertical axis against l\(^{-1}\) on the horizontal axis. Determine the slope, s, of the graph and its intercept, c on the vertical axis. Evaluate k = \(\frac{c}{s}\). Using your graph, determine the Current i when / = 55cm. State two precautions taken to ensure accurate results. (b)i. Explain what is meant by the potential difference between two points in an electric circuit. ii. State two factors on which the resistance of a resistance wire depends.

You have been provided with a metre rule, a clamp, and a set of masses. Clamp the metre rule to the edge of the bench such that 90cm of the rule projects from the edge as shown in the diagram above. Ensure that the rule is capable of performing oscillatory motion. Fix a mass M = 50g at the free end of the rule. Deflect the rule slightly such that it performs vertical oscillation. Determine the time t for 10 complete oscillations. Calculate the period T of the oscillations and evaluate T\(^{2}\) Repeat the procedure for four other values of M = 100, 150, 200, and 250g. In each case determine and record the corresponding values of t, T, and T\(^{2}\). Tabulate your readings. Plot a graph of T\(^{2}\) on the vertical axis against M on the horizontal axis, starting both axes from the origin (0,0). Determine the slopes, of the graph and its intercept C on the vertical axis. Evaluate k = 4\(\pi\)/s. [Take \(\pi\) = \(\frac{22}{7}\)]. From your graph, determine the period T, when M= 180g. State two precautions taken to ensure accurate results. (b)i. Explain simple harmonic motion. ii. Define period and frequency, with respect to a simple harmonic motion. Precautions: l ensured that the metre rule was firmly clamped Readings were repeated Parallax was avoided when readings on the stopwatch/clock were taken. zero error was noted and corrected on the stopwatch/clock. (b)i. Simple harmonic motion is a motion in which the acceleration is proportional to the displacement from a fixed point and is directed towards the point. ii. Period is the time taken by an oscillatory body to make one complete oscillation. Frequency: is the number of complete oscillations performed in one second.

An object is projected from a height of 80 m above the ground with a velocity of 40ms-1 at an angle of 30^\circ to the horizontal. The time of flight [ g ≈ 10m/s\(^2\)