TECH SC P1 (English) 2020 Preparatory Question Paper

GAUTENG DEPARTMENT OF EDUCATION PREPARATORY EXAMINATION 2020 TECHNICAL SCIENCES PAPER 1 11101 TIME: 3 hours MARKS: 150 17 pages + 2 data sheets P.T.O.

TECHNICAL SCIENCES 2 (Paper 1) 11101/20 INSTRUCTIONS AND INFORMATION 1. This question paper consists of ELEVEN questions. Answer ALL the questions in the ANSWER BOOK. 2. Start EACH question on a NEW page in the ANSWER BOOK. 3. Number the answers correctly according to the numbering system used in this question paper. 4. Leave ONE line between two sub-questions, e.g. between QUESTION 2.1 and QUESTION 2.2. 5. You may use a non-programmable calculator. 6. You are advised to use the attached DATA SHEETS. 7. Round-off your FINAL numerical answers to a minimum of TWO decimal places. 8. Give brief motivations, discussions, etc. where required. 9. Write neatly and legibly. P.T.O.

TECHNICAL SCIENCES 3 (Paper 1) 11101/20 QUESTION 1: MULTIPLE-CHOICE QUESTIONS Various options are provided as possible answers to the following questions. Choose the answer and write only the letter (A – D) next to the question number (1.1 to 1.10) in the ANSWER BOOK, e.g. 1.11 D. 1.1 If a car turns a corner, you feel as if your body is being pushed against the door, because your body resists the change in the direction of motion. Which property explains this? A Inertia B Velocity C Acceleration D Displacement (2) 1.2 Two forces, F1 and F2 are applied to a crate lying on a frictionless, horizontal surface as shown in the diagram below. The magnitude of force F1 is greater than that of force F2. N w E F1 F2 S The crate will ... A accelerate towards the east. B accelerate towards the west. C move at a constant speed towards the east. D move at a constant speed towards the west. (2) P.T.O.

TECHNICAL SCIENCES 4 (Paper 1) 11101/20 1.3 Airbags in modern cars provide more safety during an accident as shown in the picture below. Which of the statements below, made by a learner, explains how airbags can ensure better safety in a collision? (i) The time of impact increases. (ii) The impact force decreases. (iii) Both the time of impact and the force increase. A (i) only B (ii) only C (ii) and (iii) only D (i) and (ii) only (2) 1.4 Work is defined as: A The sum of the force applied on an object and the displacement in the direction of the force B The product of the force applied on an object and the displacement in the direction of the force C The difference between the force applied on an object and the displacement in the direction of the force D Half the sum of the force applied on an object and the displacement in the direction of the force (2) P.T.O.

TECHNICAL SCIENCES 5 (Paper 1) 11101/20 1.5 A force is acting on a solid plastic beam as showed in the picture below. The beam bends but when the force is removed the plastic beam returns to its position as shown below. This happens because … A it has a very small deforming force. B it has a very big deforming force. C it is a perfectly elastic body. D it is a perfectly plastic body. (2) 1.6 Which of the following will increase the viscosity of motor oil? A Decrease in the mass of the oil B Increase in the mass of the oil C Decrease in the pressure of the oil D Decrease in the temperature of the oil (2) 1.7 Hooke's law gives a relationship between stress and strain. Which of the following is the CORRECT relationship between stress and strain according to Hooke's law? A Stress is directly proportional to strain within the limit of elasticity. B Stress is inversely proportional to strain within the limit of elasticity. C Strain is inversely proportional to the stress that causes it, if elasticity is not exceeded. D Strain is directly proportional to the stress that causes it, even if the limit of elasticity is exceeded. (2) P.T.O.

TECHNICAL SCIENCES 6 (Paper 1) 11101/20 1.8 Which equation is used to calculate fluid pressure? A 𝐹1 𝐹2 = 𝐴1 𝐴2 B 𝐹 P= 𝐴 C P = gh D F1A1 = F2A2 (2) 1.9 The diagram below shows a parallel plate capacitor with plates separated by distance d. Separation d A, plate area V (battery) One way of increasing the capacitance of this capacitor is to … A decrease the area of the plates. B increase the area of the plates. C increase the distance between the plates. D decrease the constant ε0 (permittivity of free space). (2) P.T.O.

TECHNICAL SCIENCES 7 (Paper 1) 11101/20 1.10 A simplified diagram of an electric motor is shown below. When the switch is closed, coil ABCD rotates … A clockwise. B anticlockwise. C clockwise until it reaches the vertical position and then reverses its direction. D anticlockwise until it reaches the vertical position and then reverses its direction. (2) [20] P.T.O.

TECHNICAL SCIENCES 8 (Paper 1) 11101/20 QUESTION 2 (Start on a new page.) During resistance training, Jack runs at a constant velocity of 8 m. s-1 on a horizontal track. He pulls two large blocks (A of mass 10 kg and B of mass 15 kg) attached to each other with a light inextensible rope with force F as shown in the diagram below. The rope attached to Jack makes an angle of 14o with the horizontal. 2.1 State Newton’s Second Law of Motion in words. (2) 2.2 The kinetic friction coefficient between the blocks and the surface is 0,6. 2.2.1 Draw a labelled, free-body diagram of all the forces acting on block B. (5) 2.2.2 Calculate the magnitude of the frictional force on block B. (3) 2.2.3 Calculate the magnitude of force F applied by Jack. (6) 2.3 The rope between the blocks breaks unexpectedly. Calculate the acceleration of the block B directly after the rope breaks. (3) P.T.O.

TECHNICAL SCIENCES 9 (Paper 1) 11101/20 2.4 Two girls sitting on skateboards push each other with their feet as shown in the picture below. 2.4.1 Which of Newton’s laws is demonstrated in the picture above? (1) 2.4.2 State the law in QUESTION 2.4.1 above. (2) [22] P.T.O.

TECHNICAL SCIENCES 10 (Paper 1) 11101/20 QUESTION 3 (Start on a new page.) A wooden block of mass 2 kg, moving at a velocity of 5 m.s-1, collides with a crate of mass 9 kg resting on a flat horizontal surface as shown in the diagram below. After the collision, the crate moves to the right at 1 m.s-1. Ignore the effects of friction. 3.1 State the principle of conservation of linear momentum in words. (2) 3.2 Calculate the magnitude of the velocity of the wooden block immediately after the collision. (4) 3.3 If the collision lasts 0,6 seconds, calculate the force that the wooden block exerts on the crate during the collision. (4) 3.4 Calculate the impulse of the wooden block. (3) [13] P.T.O.

TECHNICAL SCIENCES 11 (Paper 1) 11101/20 QUESTION 4 (Start on a new page.) The diagram below shows a car ride (mass 500 kg) at the fair where the passengers are lifted vertically before being allowed to drop in free fall. The speed of the car ride at 40 m is 1,97 m s-1. 4.1 Define the term work. (2) 4.2 Is work a scalar or a vector quantity? (1) 4.3 State the principle of conservation of mechanical energy in words. (2) 4.4 Calculate: 4.4.1 Gravitational potential energy when the car has been lifted to a height of 48 m. (3) 4.4.2 Calculate the mechanical energy of the car at 48 m. (4) [12] P.T.O.

TECHNICAL SCIENCES 12 (Paper 1) 11101/20 QUESTION 5 (Start on a new page.) The SABS was asked to do a few elasticity tests on a new metal rod that has been developed for the motor industry. 5.1 Define the term elastic limits. (2) 5.2 The round rod is 305 mm in length and has a diameter of 32 mm. The tension test measured 67 kN of force and resulted in 0,26 mm of lengthening of the rod. Calculate the … 5.2.1 surface area of the rod. (2) 5.2.2 stress in the rod. (3) 5.2.3 strain in the rod. . (2) 5.2.4 elasticity modulus. (4) [13] QUESTION 6 (Start on a new page.) 6.1 Define the term viscosity. (2) 6.2 Does toothpaste have a high or low viscosity? (1) 6.3 Explain your answer to QUESTION 6.2. (1) 6.4 A group of learners decided to conduct an experiment to determine the effect of temperature on the viscosity of honey. Viscosity (mPa.s) Temperature (˚C) 14 000 20 8 000 24 6 000 26 5 000 28 4 000 30 2 000 34 1 000 40 6.4.1 Draw a line graph of the results of the test with viscosity on the Y-axis and temperature on the X-axis. (5) 6.4.2 Explain how the change in temperature of honey affects its viscosity. (2) [11] P.T.O.

TECHNICAL SCIENCES 13 (Paper 1) 11101/20 QUESTION 7 (Start on a new page.) A spouting can, shown below is filled with water. It has 3 holes on the side from which water flows out. The water level is at 30 cm from the bottom of the can. The density of the water in the can is 1 000 kg.m-3. The top hole is 4 cm from the top, the middle hole is 15 cm from the top and the bottom hole is 25 cm from the top. 7.1 Give TWO factors which influence the pressure in the can of water. (2) 7.2 Use calculations to prove which hole (top or bottom) has the most fluid pressure. (6) [8] P.T.O.

TECHNICAL SCIENCES 14 (Paper 1) 11101/20 QUESTION 8 (Start on a new page.) 8.1 State Pascal’s law in words. (2) 8.2 Give THREE uses of hydraulics in technology. (3) 8.3 A car is being lifted at a workshop on a hydraulic lift. The pressure at F1 is 2 000 Pa. The cylinder surface at F2 is 0,5 m2. F1 F2 Calculate the force that is applied on the car at F2. (3) [8] P.T.O.

TECHNICAL SCIENCES 15 (Paper 1) 11101/20 QUESTION 9 (Start on a new page.) 9.1 Define the term capacitor. (2) 9.2 Two parallel plates are arranged to form a capacitor. Each plate has an area of 1 m2. The plates are separated by a 2 mm gap of air. 9.2.1 Calculate the capacitance of the capacitor. (4) The capacitor in the diagram below is connected across a 200 V power source. 9.2.2 Calculate the charge that accumulates on each plate. (3) 9.2.3 How can the amount of the charge stored on each plate be increased without altering the design of the capacitor? (2) 9.2.4 Write down the general name for the insulating material that is used to fill the space between the plates of a capacitor. (1) 9.3 Tebogo wires up his bicycle lamp so that the battery will light the lamp even if he pedals slowly. He wants to connect one diode (A) which prevents the dynamo from driving current through the battery and another diode (B) which prevents the battery from driving current through the dynamo. 9.3.1 Which diode (A or B) will not allow current to flow through to the lamp? (1) 9.3.2 Explain the reason for the answer to QUESTION 9.3.1. (2) [15] P.T.O.

TECHNICAL SCIENCES 16 (Paper 1) 11101/20 QUESTION 10 (Start on a new page). The battery in the circuit diagram below has an emf (total potential difference) of 12 V. The resistance of the connecting wires and the ammeter is negligible. Calculate the … 10.1 total resistance of the circuit. (4) 10.2 total current in the circuit. (3) 10.3 power for the 1  resistor. (3) 10.4 energy dissipated in the 1  resistor in 20 s. (3) [13] P.T.O.

TECHNICAL SCIENCES 17 (Paper 1) 11101/20 QUESTION 11 (Start on a new page.) 11.1 The diagram below shows a transformer that has 1 200 turns on the primary coil and 60 turns on the secondary coil. The secondary voltage is 24 volts. 11.1.1 Is this a step-up transformer or a step-down transformer? Give a reason for your answer. (2) 11.1.2 Calculate the primary voltage for this transformer. (3) 11.2 Write down TWO structural differences between AC and DC generators. (2) 11.3 An AC generator produces a peak current (Vmax) of 5,9 A when connected to an electrical heater of resistance 46 Ω. 11.3.1 Calculate the rms current produced by the generator. (4) 11.3.2 Calculate the peak voltage (Vmax) output of the generator. (4) [15] TOTAL: 150 END

TECHNICAL SCIENCES 18 (Paper 1) 11101/20 DATA FOR TECHNICAL SCIENCES – GRADE 12 PAPER 1 INFORMATION SHEETS – PAPER 1 TABLE 1: PHYSICAL CONSTANTS NAME SYMBOL VALUE Acceleration due to gravity g 9,8 m·s-2 Permittivity of free space o 8,85 x 10-12 Fm-1 TABLE 2: FORMULAE FORCE Fnet = ma p= mv = sN fk = kN max fs Fnet Δt = Δp Fg =mg Δp = mv f - mv i WORK, ENERGY AND POWER W =Fx cos  U= mgh or EP = mgh 1 1 K= mv 2 or Ek = mv 2 K = K f − Ki or Ek = Ekf − Eki 2 2 Pave = Fvave W P= t ME = Ek + Ep ELASTICITY, VISCOSITY AND HYDRAULICS F Force Δ = / Stress = Area ε= Change in length / Strain = Original length A L F1 F2 P = gh = A1 A 2 σ stress Force = K / modulus of elasticity = strain Pressure (P) = Area ε

TECHNICAL SCIENCES 19 (Paper 1) 11101/20 ELECTROSTATICS  εο Α εο Α V C= C= E= d and d d Q C= V CURRENT ELECTRICITY V R= q=I  t I W W = VQ P= W = VI  t Δt W = I2R  t P = VI V 2 Δt P = I 2R W= R V2 P= R Rs = R1 + R2 + ... 1 1 1 = + + ... Rp R1 R 2 ELECTROMAGNETISM Δ  = BA ɛ = −N Δt Vs Ns = Vp Np