Engineering *S54683A0119* Pearson BTEC Level 3 Nationals

Transcription

1 Pearson BTEC Level 3 Nationals Write your name here Surname Forename Learner Registration Number Centre Number Engineering Unit 1: Engineering Principles Extended Certificate, Foundation Diploma, Diploma, Extended Diploma in Engineering and all titles Manufacturing / Aeronautical / Computer / Electrical and Electronic / Mechanical Engineering. Sample assessment material for first teaching September 2016 Time: 2 hours You must have: Information booklet of formulae and constants Ruler, protractor, pencil and calculator Level 3 Total marks Instructions Use black ink or ball-point pen. Show all your working, use the appropriate units in your answers and always answer to an appropriate degree of accuracy. Fill in the boxes at the top of this page with your name, centre number and learner registration number. Answer all questions. Answer the questions in the spaces provided there may be more space than you need. Information The total mark for this paper is 80. The marks for each question are shown in grey boxes use this as a guide as to how much time to spend on each question. You may use a non-programmable calculator that does not have the facility for symbolic algebra manipulation or allow the storage and retrieval of mathematical formulae. Advice Read each question carefully before you start to answer it. This paper is divided into three sections (A, B and C). Try to answer every question. Check your answers if you have time at the end. Paper reference 31706H S54683A 2016 Pearson Education Ltd. 1/1/1/1/1/1/1/1/1 *S54683A0119* Turn over

2 SECTION A Applied Mathematics Answer ALL questions. Write your answers in the spaces provided. The diagram shows a straight line graph that represents the run down time for an item of machinery. y x 1 Find the equation of the straight line graph. Total for Question 1 = 2 marks 2 *S54683A0219*

3 The diagram shows a radio transmission tower as viewed from two points A and B. The height of the tower is 32 m. C 32 m A D B Diagram not to scale 2 Calculate the distance between points A and B. Total for Question 2 = 2 marks *S54683A0319* 3 Turn over

4 The diagram shows an example of a plumb bob that is manufactured as a casting by an engineering organisation Diagram not to scale 3 Calculate the volume of the plumb bob. Total for Question 3 = 3 marks 4 *S54683A0419*

5 The percentage increase in signal strength produced by an amplifier is represented by the equation Percentage increase = (3y 2 t) 3 (yt 2 ) -2 4 Solve the equation to find the value of y when the percentage increase is 62% and the value of t = 0.5. Show evidence of the use of the laws of indices in your answer. END OF SECTION Total for Question 4 = 4 marks TOTAL FOR SECTION A = 11 MARKS *S54683A0519* 5 Turn over

6 SECTION B Mechanical and Electrical, Electronic Principles Use appropriate units in your answers. A spherical tank of diameter 5 m is used to store a gas that has a temperature of 290 K and a pressure of 50 kpa. The temperature of the gas is reduced by 20 K and the volume of the gas remains constant. 5 Calculate the pressure of the gas following the reduction in temperature. Total for Question 5 = 2 marks A container with a mass of 3 kg is dropped from a height of 4.5 m to the ground. 6 Calculate the velocity of the container when it hits the ground. Total for Question 6 = 2 marks 6 *S54683A0619*

7 A technician has been asked to carry out experiments on two components that have the same physical dimensions to investigate the density of the two components. 7 (a) Describe how the technician can use Archimedes Principle to find out which component has the lowest density. 2 marks (b) The weight of one component is known to be 0.22 N in air, 0.2 N in water and N in a liquid of unknown density. Calculate the density of the component and of the unknown liquid. 4 marks Density of component:... Density of liquid:... Total for Question 7 = 6 marks *S54683A0719* 7 Turn over

8 An electronics engineering technician has been asked to find the temperature coefficient of resistance of a length of nickel conductor. The technician has carried out some investigations and has recorded the following measurements. Temperature Resistance 20 C 15 Ohms 40 C 16.8 Ohms 8 Calculate the temperature coefficient of the nickel conductor. Total for Question 8 = 2 marks 8 *S54683A0819*

9 The diagram shows a steel plate that is pivoted around a point P. The plate is attached to four cables that are in tension. 5kN 3kN P 4kN 2kN 9 Calculate the magnitude and direction of the line of action of the resultant force relative to the point P. Magnitude:... Direction:... Total for Question 9 = 7 marks *S54683A0919* 9 Turn over

10 The diagram shows a connection between two steel sections that is held together by a 12 mm diameter bolt. 10 Calculate the shear stress on the bolt. Total for Question 10 = 4 marks 10 *S54683A01019*

11 The circuit diagram shows a DC power supply connected to three capacitors in parallel. Each capacitor is fully charged. + V1 120 V C1 68pF C2 560nF C3 680pF 11 Calculate the energy stored in each capacitor. Capacitor C1... Capacitor C2... Capacitor C3... Total for Question 11 = 3 marks *S54683A01119* 11 Turn over

12 A 2 kg block of ice has been stored in a chiller at a constant 0 C. In order to carry out an investigation, the block of ice needs to be turned into water at a temperature of 75 C. 12 Calculate how much heat energy is required to change the block of ice into water at 75 C. Assume the specific heat capacity of water is 4200 J/kg C and the specific latent heat of fusion of water is 334 KJ/kg C. Total for Question 12 = 5 marks 12 *S54683A01219*

13 Flux density (B) An experiment is being carried out on a coil of 600 turns that is wound around a closed cast steel core. The coil has a length of 1000 mm and a cross sectional area of 500 mm 2. A BH curve has been produced from the experiment Magnetic field strength (H) 13 Calculate the current required to create a flux of 0.7 mwb in the core. Total for Question 13 = 5 marks *S54683A01319* 13 Turn over

14 An electrical engineer has been investigating the braking systems of hybrid powered vehicles. 14 Explain two reasons why making use of eddy currents created in the motor/generator of hybrid powered vehicles would make the braking system more efficient Total for Question 14 = 4 marks 14 *S54683A01419*

15 An electronics test bench is fitted with a variable alternating current (AC) supply that is used for testing devices such as transformers and other electromagnetic equipment. The electricity supply has a periodic time of 30 ms at a current of 18 ma and has an inductance of 60 H. 15 Calculate the peak voltage of the AC supply to the bench. Total for Question 15 = 7 marks *S54683A01519* 15 Turn over

16 The diagram shows a network of resistors connected to two direct current power supplies. R1 5.6 R2 6 + R3 12 R V1 25 V V2 12 V 16 Calculate the power dissipated by resistor R 3. END OF SECTION Total for Question 16 = 8 marks TOTAL FOR SECTION B = 55 MARKS 16 *S54683A01619*

17 BLANK PAGE SECTION C BEGINS ON THE NEXT PAGE. *S54683A01719* 17 Turn over

18 SECTION C Synoptic Questions Answer ALL questions. Write your answers in the spaces provided. A two post 4000 kg car lift uses a 230 V electric motor to drive a mechanical lifting system. It is able to lift a 4000 kg vehicle to a height of 2 m from the floor in a time of 40s. The motor draws a current of 25 A and has an efficiency of 65%. Electric motor 2 metre limit 17 (a) Calculate the power output from the motor to the mechanical system. 4 marks 18 *S54683A01819*

19 (b) Calculate the overall efficiency of the electromechanical system. 8 marks (c) Explain one way that using pulleys could improve the overall system efficiency of the vehicle lifting system. 2 marks END OF EXAM *S54683A01919* Total for Question 17 = 14 marks TOTAL FOR SECTION C = 14 MARKS TOTAL FOR PAPER = 80 MARKS 19