**PHYSICS PAPER 2 MAY/JUNE 2007**

**Question 1**

**A particle is projected at an angle of 30° to the horizontal with a speed of 250 ms-1**

** Calculate the ,**

** (a)total time of flight of the particle;**

** (b)speed of the particle at its maximum height [g =10 ms-2]**

**Question 2**

**A stone projected horizontally from the top of a tower with a speed of 4ms-1 lands on the level ground at a horizontal distance 25m from the foot of the tower. Calculate the height of the tower. [g = 10ms-2]**

**Question 3**

**State**

** (a)the difference between place polarized light and ordinary light;**

** (b)two uses of Polaroid**

**Question 4
**

**Define**

**(a)electrolysis;**

**(b)electrolyte;**

**(c)electrode.**

**Question 5**

**Copper of thickness d is plated on the cathode of a copper voltammeter. If the total surface area of the cathode is 60 cm2 and a steady current of 5.0 A is maintained in the voltammeter for 1 hour, calculate the value of d.**

** [Density of copper = 8.9 x 103 kg m-3]**

** [Electro chemical equivalent of copper = 3.3 x 10-7 kg C-1]**

**Question 6**

**(a)Explain thermionic emission.**

**(b)State two applications of electrical conduction through gases.**

**Question 7**

**Define**

** (a)tensile stress;**

** (b)tensile strain;**

** (c)yield point.**

**Question 8**

**A wire of length 5.0 m and diameter 2.0 mm extends by 0.25 when a force of 50 N was used to stretch it from its end. Calculate the**

** (a)stress in the wire**

** (b)strain in the wire.**

** [π = 3.142]**

**Question 9**

**(a) List two factors that can affect the rate of diffusion.**

**(b) State two examples to illustrate the effects of the surface tension.**

**Question 10**

**State two effects to show**

**1. the existence of matter waves**

** 2. that radiation behaves like particles**

**Question 11**

**(a)State the conditions of equilibrium for a number of coplanar parallel forces [2 marks]**

**(b)A metre rule is found’ to balance horizontally at the 48 cm mark. When a body of mass 60g is suspended at the 6 cm; mark the balance point is found to be at the 30 cm mark. Calculate the**

** (i)mass of the metre rule**

** (ii)distance of the balance point from the zero end, if the body were moved to the 13 cm mark. [6 marks]**

**(c)A man pulls up a box of mass 70 kg using an inclined plane of effective length 5 m unto a platform 2.5m high at a uniform speed. If the frictional force between the box and the plane is 1000 N**

** (i)draw a diagram to illustrate all the forces acting on the box while in motion;**

** (ii)calculate the**

**I.minimum effort applied in pulling up the box;**

** II.velocity ratio of the plane if it is inclined at 300**

** III.force ratio of the plane. [ 7 marks]**

**Question 12**

**(a)Define the boiling point of a liquid. [ 2 marks]**

**(b)With the aid of a sketch diagram, describe an experiment to determine the boiling point of a small quantity of a liquid. [8 marks]**

**(c) A piece of copper of mass 300g at a temperature of 9500 C is quickly transferred into a vessel of negligible thermal capacity containing 250g of water at 250 C. If the final steady temperature of the mixture is 1000 C, calculate the mass of water that will boil away.**

**specific heat capacity of copper = 4.0 x102 J kg2 K-1**

** specific heat capacity of water = 4.2 x 103 J kg•1 K-1 .**

** specific latent heat of vaporization of steam = 2.26 x l06 J kg -1 [5 marks]**

**Question 13**

**(a)(i)what is a wave motion? [2 marks]**

** (ii)State two differences between a radio wave and a sound wave. [2 marks]**

**(b)(i) Given that you are provided with a tuning fork, a burette and other necessary apparatus, describe with the aid of a diagram, an experiment to determine the frequency of a note emitted by a source of sound. [6 marks]**

** [Assume the velocity of sound in air is known]**

**(ii)State two precautions necessary to obtain accurate result in the experiment described in 13(b) (i) above. [2 marks]**

**(c)A pipe closed at one end is 100 cm long. If the air in the pipe is set into vibration and a fundamental note is produced, calculate the frequency of the note.**

** [velocity of sound in air = 340 ms-1] [ 3 marks]**

**Question 14**

**(a) With the aid of simple diagram, explain how a step down transformer works. [7 marks]**

**(b) (i) State three ways by which energy is lost in a transformer.**

** (ii) Mention how each of the losses in (b) (i) above can be minimized. [3 marks]**

**(c) A 95% efficient transformer is used to operate a lamp rated 60 W, 220 V from a 4400 V a.c. supply. Calculate the**

** (i)ratio of the number of turns in the primary coil to the number of turns in the secondary coil of the transformer;**

** (ii)current taken from the mains circuit. [5 marks]**

**Question 15**

**(a) (i) With the aid of a labelled diagram, describe the mode of operation of a modern X-ay tube. [8 marks]**

** (ii)State the energy transformations that take place during the operation of the X-ray tube. [2 marks]**

**(b)Define, as applied to X- rays, the following terms:**

**(i) hardness;**

** (ii) intensity.**

**PHYSICS PAPER 2 OCT/NOV 2007**

**Question 1**

**A stone projected horizontally from the top of a vertical wall with a velocity of 25ms-1 hits the horizontal ground at a point 60 m from the base of the wall. Calculate the time of flight of the stone.**** [g = 10 ms-2]**

**Question 2**

**A projectile is fired vertically upwards with an initial velocity of 30 ms-1. Using the law of conservation of energy, determine the maximum height attained by the projectile.**

**Question 3**

**(a) List three types of waves, other than light, that can be plane polarized. [3 marks]**

**(b) State three methods of polarizing an unpolarized light. [3 marks]**

**Question 4**

**(a) List the factors which determine the mass of an element deposited or liberated during electrolysis.**

**[2 marks]**

**(b) Classify the following liquids into electrolytes and non electrolytes:**

** distilled water;**

** alkalis;**

** alcohols;**

** salt solution. [3 marks] **

**Question 5**

**1. A current of 3A passes through a water voltameter for 20 minutes. Calculate the volume of oxygen liberated in the voltameter at s.t.p**

** {electrochemical equivalent of oxygen at s.t.p. = 830 x 10-8 kg C-1}**

** { density of oxygen at s.t.p. = 1.33 kg m-3 **

**Question 6**

**A wire of length 62.8 cm and diameter 1.0mm is stretched by 2.0 mm. If the young’s modulus of the material of the wire is 2.0 x Nm-2, calculate the tension in the string.**

**[Take π = 3.142]**

**Question 7**

**(a) Define force constant. [1 mark]**

**(b) The force constant of a spring is 320 Nm-1. Calculate the energy stored in the spring when it is compressed by 1.5 cm. [2 mark]**

**Question 8**

**(a) Explain how a gas can be made to conduct electricity. **

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

**Question 9**

**A capillary tube of radius 5.0 x 10-5 m is dipped vertically into water contained in a trough. If the surface tension of water is 0.073 Nm-1 and the angle of contact between water and the material of the tube is negligible, determine how high the water will rise in the tube above the surface of the water in the trough.**

** [density of water = 1.0 x 103 kg m-3, g = 10 ms-2]**

**Question 10**

**(a) Explain wave-particle duality of light. [1 mark]**

**(a) Mention two phenomena that can only be explained in terms of the particulate nature of light. **

**[2 marks]**

**Question 11**

**(a) (i) Define upthrust. [2 marks]**

** (ii) State Arcmedes; principle. [2 marks]**

** (iii) State the law of flotation. [2 marks]**

**(b) An open tank contains a liquid of density 1.20 x 103 kg m-3. A body whose volume and density are 5.0 x 10-3 m3 and 9.0 x 102 kg m-3 respectively is attached with a thread to the bottom of the tank such that it is totally immersed in the liquid.**

**[Assume that the liquid in the tank is still]**

**(i) Draw a diagram of the arrangement and indicate the forces acting on the body. [4 marks]**

**(ii) Determine the tension in the thread [4 marks]**

**(iii)State what happens if the thread is cut off. [4 marks] **** [ g = 10 ms-2]**

**Question 12**

**(a) (i) State the principle of conservation of energy. [2 marks]**

** (ii) With the aid of a diagram, explain the energy transformations in a swinging simple pendulum.**

**[2 marks]**

**(b) (i) Describe an experiment to determine the specific heat capacity of a solid by the method of mixtures.**

**(ii) State two precautions required to obtain accurate results in the experiment in (b)(i) above.**

**[10 marks]**

**Question 13**

**(a) Define, with respect to a progressive wave,**

** (i) wavelength;**

** (ii) frequency;**

** (iii) speed [3 marks]**

**(b) (i) State the relationship among the terms defined in13(a) above [1 mark]**

** (ii) How are stationary waves produced? [3 marks]**

**(c) The equation y = a sin (ωt – kx) represents a plane wave traveling in a medium, where y is the displacement in metres at a distance x metres and time t in seconds.**

** If a = 1.0 c 10-7 m, ω = 6.6 x 103 rad s-1 and k = 20 m-1, determine, for the wave, the**

**(i) wavelength;**

**(ii) speed;**

**(iii) period;**

**(iv) maximum speed of a particle of the medium. **** [take π =22/7)**** [8 marks] **

**Question 14**

**(a) (i) State Coulomb’s law of electrostatics. [2 marks]**

** (ii) Define electric field intensity at a point in an electric field. [2 marks]**

** (iii) Draw a diagram to illustrate the electric field pattern due to two positive charges near each other. [2 marks]**

**(b) The magnitude of the electrostatic force between two point charges is**

**given by the equation F = k q1q2/****r2** ,** **

**(i) Identify each of the other symbols in the equation;**

**(ii) State the unit of each symbol identified. [4 marks]**

**(c) A positive charge of 1.6 x 10-12 C is located 5 cm away from a point x.**

** Calculate the**

**(i) electric potential at x;**

**(ii) work done on a similar charge brought from infinity to x.**

**[Take 1/4πEO = 9.0 x 109 mF-1]**

**Question 15**

**(a) Explain the following terms:**

** (i) ground state energy;**

** (ii) excitation energy;**

** (iii) emission line spectra.**

**(b) The surface of a metal of work function 3.20 x 10-19 J is illuminated with A radiation of wavelength 3.50 x 10-7 m. Calculate the **

** (i) frequency of the incident radiation;**

** (ii) energy of the incident radiation;**

** (iii) kinetic energy of the most energetic electrons.**

**[ c = 3.0 x 108 ms-1, e = 1.6 x 10-19C, h = 6.6 x 10-34 Js]**

**SOURCE: WAEC**