PHYSICS 1 Past Paper PDF - Form Six Pre-Mock Examination - August 2024

THE UNITED REPUBLIC OF TANZANIA PRESIDENT’S OFFICE REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT NJOMBE REGION FORM SIX PRE-MOCK EXAMINATION 131/1 PHYSICS 1 (For Both...

THE UNITED REPUBLIC OF TANZANIA PRESIDENT’S OFFICE REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT NJOMBE REGION FORM SIX PRE-MOCK EXAMINATION 131/1 PHYSICS 1 (For Both School and Private Candidate) Time 3 Hours August 2024 Instructions INSTRUCTIONS: 1. This paper consists of section A and B with a total ten (10) questions. 2. Answer all questions in section A and choose two (2) questions from section B. 3. Marks for each question part are there of indicated. 4. Mathematical tables and non-programmable calculators may be used. 5. Circular phones and any unauthorized materials are not allowed in the examination room. 6. Write you name on every page of your answer sheet(s) 7. Whenever necessary the following may be used; a) Radius of the earth = 6400km. b) Thermal conductivity of brass = 109 𝐽𝑠 −1𝑚−1 °𝐶 −1 ; c) Heat of vapourisation of water = 2256 𝐽𝑘𝑔−1. d) Acceleration due to gravity, 𝑔 = 10 𝑚 𝑠 2. Page 1 of 4  SECTION A (70 MARKS) Answer ALL questions in this section 1. (a) (i) Explain the principle of homogeniety of dimensions. What are its uses? Give Example (3 marks) (ii) The measurement value of length of a simple pendulum is 20 cm known with 2 mm accuracy. The time for 50 oscillations was measured to be 40 s within 1 s resolution. Calculate the percentage accuracy in the determination of acceleration due to gravity ‘g’ from the above measurement. (3marks) (b) A mass M is held at rest on an inclined plane, whose slope is , by means of horizontal force F. If the coefficient of static friction is , show that the maximum force F allowed before the body starts to move up the plane is given as ( ) 2. (a) (i) Define the term radius of gyration and state its physical meaning (2 Marks) (ii) How a swimmer jumping from a height is able to increase the number of loops made in air? (2 Marks) (b) A ring has aradius of 20 cm and a mass of 100 g, calculate the moment of inertia about an axis (i) Perpendicular to its plane through its centre. (2 Marks) (ii) Perpendicular to its plane passing through a point on its circumference. (2 Marks) (iii) In its plane passing through the centre. (2 Marks) 3. (a) (i) What are the conditions for a body to executes SHM? (1 mark) (ii) Show that a body dropped in a tunnel along Earth diameter executes Simple harmonic motion. (4 marks) (b) For a particle vibrating with Simple harmonic motion the displacement is 14 cm at the instant the velocity is 6 cm/s and the displacement is 6 cm at the instant the velocity is 14 cm/s. Assuming the amplitude is constant, calculate (i) Amplitude (2 marks) (ii) Frequency, and (2 marks) (iii) Period (1 mark) Page 2 of 4 4. (a) (i) Differentiate between centripetal force and centrifugal force (2marks) (ii) Why are the passengers of a car round a circular track thrown outward? (3marks) (b) A geostationary satellite orbits the earth at the height of nearly 36000 km from the surface of the earth. What is the potential due to earth’s gravity at the site of the satellite? Take the radius of the earth re=6400 km and mass of the earth is 𝑘𝑔 (5 Marks) 5. (a) (i) What is thermometry property? (1mark) (ii) Two thermometers are constructed in the same way except that one has a spherical bulb and: the other an elongated cylindrical bulb. Which one will respond quickly to temperature changes? Explain (3marks) (b) A particular resistance thermometer has a resistance of 30 at the ice point, 42 at the steam point and 35 when immersed in a boiling liquid. A constant- volume gas thermometer gives reading of , and at the same three temperatures. Calculate the temperature at which the liquid is boiling (i) On the scale of the gas thermometer (2marks) (ii) On the scale of the resistance thermometer (2marks) (iii) Why are the values in part (i) and (ii) different? (2marks) 6. (a) (i) Give two difference between adiabatic and isothermal processes. (2marks) (ii) The volume of a gas at atmospheric pressure is compressed adiabatically to half its original volume. Calculate the resulting pressure (gamma = 1.4) (3marks) (b) (i) When a gas expands adiabatically, it does work on its surroundings. But if there is no heat input to the gas, where does the energy come from to do work? (1mark) (ii) Show that for adiabatic process in an ideal gas, the relationship between the volume (V) of the gas and temperature (T) is given by ( ) (4marks) 7. (a) (i) What is mulching? (1 mark) (ii) What are three importance of mulching to plants? (3 marks) (b) (i) A wind turbine works in opposite to that of a fan. Justify your answer (2 marks) (ii) One of the major environmental concern to, is the destruction of ozone layer. What are the reasons for this concern? (4 marks) SECTION B. (30 Marks) Answer any two question from this section 8. (a) (i) What are the importance of root mean square value of an A.C? (2marks) Page 3 of 4  (ii) An a.c circuit of frequency 50 Hz has a maximum current of 100 A. Write down an equation for the instantaneous values of the current and find the instantaneous values after 1/360 seconds. (3marks) (b) (i) Distinguish between reactance and the resistance of acoil, and show how they are related. (2marks) (ii) A person is made to walk through the entrance of a metal detector, for security reasons. If the person is carrying anything made of a metal, the metal detector emits a sound waves. Explain the principle of operation of the metal detector (3marks) (c) Determine the phase angle and power factor for RLC series circuit containing a resistor of 50 , a capacitor of 10 and an inductor of 0.45 H, when connected to a power supply with frequency of 60 Hz. (5marks) 9. (a) (i) Distinguish between intrinsic and extrinsic semiconductor (2marks) (ii) Why is silicon is preferred than germanium in the manufacturing of semiconductor devices (2marks) (b) Explain the difference between conductors, semiconductors and insulators with the help of an energy band diagram. (6marks) (c) For a CE transistor amplifier, the audio signal voltage across the collector resistance of 2000 Ohms is 2.0 V. Suppose the current amplification factor of the transistor is 100. What should be the value of RB in series with VBB supply of 2.0V, if the d.c base current has to be 10 times the base signal current? (5 Marks) 10. (a) (i) What is "depletion layer" and "potential barrier" as applied in electronics (2marks) (ii) Explain the formation of depletion layer and barrier potential in pn junctions.(2marks) (b) An electrical control system uses three position sensing devices, each of which produce output high when the position is confirmed These devices are to be used in conjunction with a logic network of AND and OR gates and the output of the network is to be high when two or more of the sensing devices are producing signals of high. Draw the truth table and write it's boolean expression. (5marks) (c) (i) Give advantages and disadvantages of AM over FM (2marks) (ii) By using block diagram describe the reception of radio signals (3marks) Page 4 of 4