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Calculate the area of the shaded segment of the circle given in the figure below.
Date posted:
August 16, 2019
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Given that:
Enthalpy of combustion of Carbon (graphite) = -393kJmol-1
Enthalpy of combustion of carbon (II) oxide = -283 kJmol-1
(a) Write down the thermo-chemical equations for the combustion of:
(i) Carbon (graphite)
(ii) Carbon (II) oxide
(b) Determine the enthalpy of formation of carbon (II) oxide.
(c) Draw an energy level diagram for the processes in (a) and (b) above.
(d) State two properties of Carbon (IV) Oxide that make it suitable for use in fire extinguishers.
(e) When 8.0 g of sulphur is completely burned in oxygen in a calorimeter, the heat evolved raises the temperature of 500 cm3 of water by 35 0C. Calculate the heat of combustion of sulphur.
(The specific heat capacity of water = 
Date posted:
August 16, 2019
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Below is an equation of a straight line.
(i).Find the gradient of the line
(ii) Equation of a line passing through point (2,3) and parallel to the given line
Date posted:
August 16, 2019
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Two voltages of + 0.6V and – 1.4 V are applied to the two input resistors of a summing amplifier. The respective input resistors are 400 kilo-ohms and 100 kilo-ohms and feedback resistor is 200 kilo-ohms. Determine the output voltage.
Date posted:
August 16, 2019
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Determine the output voltage for the summing amplifier shown in Fig. 9.6
Date posted:
August 16, 2019
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Determine the output voltage for the summing amplifier shown in Fig. 9.5.
Date posted:
August 16, 2019
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Determine the output voltage for the summing amplifier in Fig. 9.4.
Date posted:
August 16, 2019
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The 2nd, 7th and 22nd terms of an arithmetic progression are the first three consecutive terms of a geometric progression. The 10th term of the arithmetic progression is 21 Determine:
a) The first term and the common difference of the A.P
b) The sum of the first six terms of the G.P
Date posted:
August 16, 2019
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The table below shows the radioactive decay for a sample of iodine -131.Study it and answer the questions that follow.
(i) Plot the decay curve of iodine -131 using the data given in the table above.
(ii) Use the graph to determine the half-life of the sample.
(iii) What fraction of the original sample remains after 18 days?
Date posted:
August 16, 2019
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The amplifier in Fig. 7.44 is being used to amplify an input signal to a peak output voltage of 100 mV. What is the maximum operating frequency of the amplifier?
Date posted:
August 16, 2019
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Determine the maximum operating frequency for the circuit shown in Fig. 7.44. The slew rate is 0.5 V/μs.
Date posted:
August 16, 2019
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An OP-amp has a gain-bandwidth product of 1.5 MHz. Find the operating bandwidth for the following closed-loop gains (i) ACL = 1 (ii) ACL = 10 (iii) ACL = 100.
Date posted:
August 16, 2019
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An OP-amp has a gain-bandwidth product of 15 MHz. Determine the bandwidth of OP- amp when ACL = 500. Also find the maximum value of ACL when f2 = 200 kHz.
Date posted:
August 16, 2019
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A slaughter house bought a number of sheep at sh 1200 each and a number of oxen at sh 15000 each. They paid a total amount of sh 135,000.lf they had bought twice as many sheep and three oxen less they would have saved sh 15000.
a) Find the number of each type of animals they bought.
b) The slaughter house sold all the animals at a profit of 30% per sheep and 35% per oxen.Determine the total profit they made.
Date posted:
August 16, 2019
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Study the diagram below and answer the questions that follow.
(i) State the observation made in the lime water. Explain.
(ii) How can the identity of substance K be demonstrated?
Date posted:
August 16, 2019
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In an experiment to determine the proportion of oxygen in air, Copper turning were packed in excess in a combustion tube connected to two syringes of 80 cm3 each in a volume . Syringe R contained 80 cm3 of air while syringe S was closed and empty as shown.
Air was passed over heated turnings slowly and repeatedly until there was no further change in volume. After cooling, 63.2 cm3 of air remained in syringe R.
(i) Why was copper packed in excess?
(ii) State one observation made in the combustion tube during experiment.
(iii) Give an equation for the reaction that took place in combustion tube.
(iv) Determine the percentage of oxygen used up during the experiment.
Date posted:
August 16, 2019
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A student at a certain college has a 60% chance of passing an examination at the first attempt.Each time a student fails and repeats the examination his chances of passing are increased by 15% Calculate the probability that a student in the college passes an examination at the second or at the third attempt.
Date posted:
August 16, 2019
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Show the schematic symbol of an operational amplifier
Date posted:
August 16, 2019
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The line passing through the point C(-1,3t) and D (t,3) is parallel to the line whose equation is 2y – 3x = 9. Write down the coordinates of C and D.
Date posted:
August 16, 2019
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Find y if log2y – 2 = log292
Date posted:
August 16, 2019
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In an experiment to separate a mixture of water (100oC) and ethanol (78.4oC), a student set up the apparatus shown below.
(a) Identify the mistakes in the set up.
(b) What method would the student use to test the purity of ethanol obtained?
Date posted:
August 16, 2019
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A ship leaves port M and sails on a bearing of 0500 heading towards Island L. Two navy destroyers sail from a noval base N to intercept the ship. Destroyer A sails such that it covers the shortest distance possible. Destroyer B sails on a bearing of 200 to L. If the bearing of N from M is 1000 and distance NM=300Km, Using a scale of 1cm to represent 50Km, determine
i) the positions of M,N and L.
ii) the distance traveled by destroyer A.
iii) the distance traveled by destroyer B.
iv) the bearing of N from L.
Date posted:
August 16, 2019
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Maru Secondary School consumes 40 bags of maize and 25 bags of beans per term. Kadu Secondary School consumes 35 bags of maize and 18 bags of beans per term. The schools purchase the grains from the same grain store. Maru pays sh.380,000 while Kadu pays sh.301,500 for the grains.
a) Write down two equations representing the cost of grains in the two schools.
b) Using matrix method , calculate the cost of each bag of maize and beans.
c) The following term the price of each bag of maize increased by 20% while that of beans decreased by 15%.
i) How much did Maru pay for the grains?
ii) If the school enrollment increased by 10% and the food ration also increased proportionally, how much would the school spend on the grains?
Date posted:
August 16, 2019
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Karis owns a farm that is triangular in shape as shown below.
a) Calculate the size of angle BAC.
b) Find the area of the farm in hectares.
c) Karis wishes to irrigate his farm using a sprinkler machine situated in the farm such that it is equidistant from points A,B and C.
i) Calculate the distance of the sprinkler from point C.
ii) The sprinkler rotates in a circular motion so that the maximum point reached by the water jets is the vertices A,B, and C. Calculate the area outside his farm that will be irrigated.
Date posted:
August 16, 2019
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Read the extract below from DOLL’S HOUSE and answer all the questions that follow.
Nora: Should? He did sign them.
Krogstad: I had left the date blank; that is to say, your father should himself have inserted the date on which he signed the paper. Do you remember that?
Nora: Yes, I think I remember—
Krogstad: Then I gave you the bond to send by post to your father. Is that not so?
Nora: Yes.
Krogstad: And you naturally did so at once, because five or six days afterwards you brought me the bond with your father's signature. And then I gave you the money.
Nora: Well, haven't I been paying it off regularly?
Krogstad: Fairly so, yes. But to come back to the matter in hand that must have been a very trying time for you, Mrs.
Nora: It was, indeed.
Krogstad: Your father was very ill, wasn't he?
Nora: He was very near his end.
Krogstad: And died soon afterwards?
Nora: Yes:
Krogstad: Tell me, Mrs Helmer, can you remember what day your father died? the month, I mean.
Nora: Papa died on the 29th of September. by any chance on what day of
Krostand: That is correct; I have ascertained it for myself. And, as that is so, there is discrepancy (taking a paper from his pocket) which I cannot account for.
Nora: What discrepancy? I don't know—
Krogstand: The discrepancy consists, Mrs. Helmer, in fact that your father signed this bond three days after his death.
Nora: What do you mean? I don't understand —
Krogstand: Your father died on the 29th of September. But, look here; your father has dated his signature the 2nd of October. It is a discrepancy, isn't it? (NORA is silent) Can you explain it to me?
(NORA is silent) It is a remarkable thing, too, that the words '2nd of October,' as well as the year, are not written in your father’s handwriting but in one that I think I know. Well, of course it can be explained; your father may have forgotten to date his signature, and someone else may have dated it haphazard before they knew of his death. There is no harm in that. It all depends on the signature of the name; and that is genuine. I suppose, Mrs. Helmer? It was your father himself who signed his name here?
Questions.
a) What is it that Nora claims to have signed? Explain.
b) What does this excerpt reveal about Krogstad's character?
c) Explain key theme brought out in the excerpt?
d) Why did Nora forge her father's signature?
e) What is the meaning of the following words as used in the excerpt?
I. Ascertained
II. Discrepancy
III. Genuine
f) Papa died on the 29th of September (Add a question tag.)
Date posted:
August 16, 2019
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John is a sales agent in a company that pays him a basic salary of sh.5000. In addition he is given a commission of 5% on sales worth sh.200, 000 and 7.5% on any additional sales above sh. 200,000.
a) In January his total sale was sh. 420,000. How much did he earn in total.
b) In February, his total earnings was sh.28125. Calculate his total sales in February.
c) The following year the company changed its policy to a flat rate commission of 9% on goods sold. In the first month, John sold goods worth sh.450,000. Find the percentage change in earning compared to the old policy.
Date posted:
August 16, 2019
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A measuring cylinder of radius 5cm contains water whose level reads 6cm high. A spherical object is immersed in the water and the new level reads 10cm. Calculate the radius of the spherical object.
Date posted:
August 16, 2019
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In the sentences below, underline the nouns that are used as adjectives.
i)Mr. Charo amused the children by reciting nursery rhyms.
(ii) When we camped in the Maasai Plains, we felt like strangers in the new environment
Date posted:
August 16, 2019
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Correct the error in the following sentences.
(i) Something is smelling awful.
(ii) This brilliance is utter.
Date posted:
August 16, 2019
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What are the possible solutions to land dereliction?
Date posted:
August 16, 2019