Science · Paper 2 · 2021
38 questions 🇹🇿 NECTA ✓ MS3-hour timed simulation · auto-graded · counts toward ranking
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Section B
b) Determine the final velocity at each round of a test. The recorded data provided were as shown. ...........................................................................................................................
- Is a decreasing velocity with time (1 mk)
- Calculate the initial velocity and uniform acceleration (0 mk)
- Determine the final velocity at each round of a test. The recorded data provided were as shown. (0 mk)
- It is a distance in a specific direction (1 mk)
- Is a path of an object from one point to another (1 mk)
- Is a rate of change of displacement (1 mk)
- Is a rate of change of velocity (1 mk)
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(c) Give one advantage and one disadvantage of using the cell ..
- Draw a leclanche cell diagram showing the structure of the cell, and name its four main components. (0 mk)
- How can the formation of a layer of hydrogen on the positive terminal in (b)(i) prevented. (0 mk)
- Give one advantage and one disadvantage of using the cell (0 mk)
- Briefly explain the effect of the formation of a layer of hydrogen on the positive terminal. (0 mk)
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A form Two teacher wrote the following statement on the blackboard ‘‘friction force is directly proportional to the normal reaction between two surfaces in contact with relative motion’’ Derive a mathematical equation represented by this statement. Using the formula obtained in (a), find the coefficient of friction where a block of 2kg is pulled on a rough horizontal surface with a force of 15N.
- Derive a mathematical equation represented by this statement: ‘friction force is directly proportional to the normal reaction between two surfaces in contact with relative motion’. (2 mk)
- Using the formula obtained in (a), find the coefficient of friction where a block of 2kg is pulled on a rough horizontal surface with a force of 15N. (3 mk)
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In an experiment of expansion of metals, student heated a steel ball to a 0 temperature of 50 C to give a diameter of 50.25 mm. The ball was then placed over a hole of diameter 50 mm. Estimate the temperature of the ball as a result of dropping it through the hole. (Consider = 0.000012/ 0 C).
- In an experiment of expansion of metals, student heated a steel ball to a 0 temperature of 50 C to give a diameter of 50.25 mm. The ball was then placed over a hole of diameter 50 mm. Estimate the temperature of the ball as a result of dropping it through the hole. (Consider = 0.000012/ 0 C). (5 mk)
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Suppose you are given a 100 g of lead shots, measuring cylinder partly full of water to a reading of 80ml. When lead shots placed into it, the reading rose to 88.8ml. Estimate the density and relative density of the lead shots.
- should be used to measure potential difference? (1 mk)
- Estimate the relative density of the lead shots. (0 mk)
- should be used to measure electric current? (1 mk)
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- In an engineering science laboratory teacher received the the following equipment: Wheelbarrow, Scissors, Spade, Nut Cracker, Tong and Fishing rod. Arrange these equipments according to their classes of lever. (0 mk)
- A student used a lever to shift a heavy iron block from one point to another during the cleanliness session in the workshop as shown in the Figure 2. Calculate the mechanical advantage of this lever. (0 mk)
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Kazimoto who is a Form Two student was pushing his books cabinet to its position after finishing the cleaning of his room. During this activity his friends Maganga, Gwalu, and Hogoma, who were watching him made a comment? (i) Maganga said: Good Kazimoto, you are so powerful as you have managed to use your energy with respect to time and power with energy to store the cabinet to its position. (ii) Gwalu commented to Maganga: Power and energy are two different things, energy is the Power per time taken and power is the ability to do work. (iii) Hogoma responded to Gwalu: Power is the rate of doing work and energy is the ability to do work. (iv) Kazimoto commented as well that, energy is the capacity to perform work while power is the energy consumed per time taken. From their arguments, who was right?
Engineering Science teacher presented the diagram shown in Figure 1 on the blackboard and asked the students to give the name of the product of the parameters ‘F’ and ‘a’ what will be the student answer to the teacher?
Section C
A form two student prepared an experiment in laboratory to determine the resistance ‘R’ of a metallic conductor. She closed the switch K, and adjusted the rheostat ‘R ’ to different positions to increase the current. For each position she recorded the readings ‘V’ and ‘I’ of the voltmeter and ammeter respectively. Table 2: I(amps) | 1 | 2 | 3 | 4 | 5 | 6 V(Volts) | 2 | 4 | 6 | 8 | 10 | 12 From the Table 2 answer the following questions.
- Find the ratio for each pair and fill the Table 2. (2 mk)
- Plot the graph of V against I (3 mk)
- Calculate the gradient ‘S’ of the graph drawn in (b) (2 mk)
- Compare the value of the gradient ‘S’ obtained in (c) and the values of the ratio obtained in (a). (2 mk)
- State the relation between S and V/I (2 mk)
- Which physical quantity is represented by the gradient ‘S’? (2 mk)
- Determine the value of the resistance ‘R’ of the metallic conductor. (4 mk)
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