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- A uniform resistance wire of length 2.0m conducts a current of 0.25A when connected in series with a cell of e.m.f of 1.6V. How much...(Solved)
A uniform resistance wire of length 2.0m conducts a current of 0.25A when connected in series with a cell of e.m.f of 1.6V. How much current would be conducted if the wire is now cut into 2 equal lengths which are then arranged in parallel.
Date posted: September 30, 2019.
- The equation bellows shows a chemical reaction that takes place in green plants under certain conditions.(Solved)
The equation bellows shows a chemical reaction that takes place in green plants under certain conditions.
a) Name the
i) Process represented by the equation
ii) Substance represent by X
b) Other than the reactants, state two conditions necessary for this reaction to occur.
c) Name three types of cells in which the process occurs
Date posted: September 30, 2019.
- Diagram below represents a metre bridge used to determine the resistance of an electrical component, X.(Solved)
Diagram below represents a metre bridge used to determine the resistance of an electrical component, X.
From the diagram,
i) Explain why wide brass strips are used as terminals.
ii) Explain why a cell of low e.m.f is preferable.
iii) If null deflection was obtained when l1 was 60.0cm. Calculate the resistance of component marked X.
iv) State three ways of ensuring that the error is minimized.
Date posted: September 30, 2019.
- Diagram below is a resistor-capacitor circuit. At time t = 0, the switch is closed at A for some time and then opened. The switch...(Solved)
Diagram below is a resistor-capacitor circuit. At time t = 0, the switch is closed at A for some time and then opened. The switch is then closed at B for some time.
On the axes provided below, sketch graph of voltage V across the capacitor against time t (t1 and t2 represent time for opening at A and closing at B respectively).
Date posted: September 30, 2019.
- Two herbivorous mammal species were introduced into an ecosystem at the same time and in equal numbers. The graph below represents their populations during the...(Solved)
Two herbivorous mammal species were introduced into an ecosystem at the same time and in equal numbers. The graph below represents their populations during the first seven years. Study the graph and answer the questions that follow.
(a) (i) Which species has a better competitive ability?
(ii) Give a reason for your answer.
(b) Account for the shape of the curve for spicies A between;
(i) One year and three years
(ii) 4 years and eight years.
(c) A natural predator of species A was introduced into the ecosystem. With a reason, state how the
population of each species would be affected?
(d) State four other biotic factors of the ecosystem which affects organisms distribution in their habitat other than the one illustrated in the above graph.
(e) Name the instruments used to measure the following;
(i) Light intensity.
(ii) Light penetration in water.
(iii) Speed of wind.
(iv) Atmospheric pressure
Date posted: September 30, 2019.
- A small coin lies at the bottom of a water pond at a depth of 1.2m. How far from the water surface does the observer...(Solved)
A small coin lies at the bottom of a water pond at a depth of 1.2m. How far from the water surface does the observer see it,given the speed of light in water is 2.3 x 108m/s and velocity of light in air is 3.0 x 108m/s.
Date posted: September 30, 2019.
- (a) Name two substances transported in blood plasma.
(i)
(ii)
(b) Wanjiru is blood group A.
(i) Name an antibody found in her blood plasma.
(ii) Name...(Solved)
(a) Name two substances transported in blood plasma.
(i)
(ii)
(b) Wanjiru is blood group A.
(i) Name an antibody found in her blood plasma.
(ii) Name an antigen found in her red blood cell.
(iii) Name the blood groups she can donate to
Blood groups-
(i)
(ii)
(c) What is meant by the term allergy?
(d) Name one substance that can cause allergy
Date posted: September 30, 2019.
- The figure below shows two spherical materials, one an insulation conductor and the other a conductor. Negative charges are introduced at point A in each...(Solved)
The figure below shows two spherical materials, one an insulation conductor and the other a conductor. Negative charges are introduced at point A in each case.
On the same figure indicate the final position of the charges. Explain your answer.
Date posted: September 30, 2019.
- The diagram below represents two process underwent by a plant cell.(Solved)
The diagram below represents two process underwent by a plant cell.
(a) Identify process X
(b) Name the state of the cell after undergoing process
(i) X.
(ii) Z .
(c) Name the substance which is found in parts labelled;
(i) P.
(ii) Y .
(d) Name parts labelled M and Q.
(e) Name the cell organelle which is usually referred to as 'cell’s kitchen'.
Date posted: September 30, 2019.
- The figure below shows a plastic bottle having a weighted cork floating on water inside the bottle.When the sides of the bottle are squeezed the...(Solved)
The figure below shows a plastic bottle having a weighted cork floating on water inside the bottle.When the sides of the bottle are squeezed the cork sinks.
Explain the observation.
Date posted: September 30, 2019.
- 50g of ice at -5oC is dropped in a well lagged copper calorimeter of mass 30g having 150g of water at 80oC. A final steady...(Solved)
50g of ice at -5oC is dropped in a well lagged copper calorimeter of mass 30g having 150g of water at 80oC. A final steady temperature of 35oC is attained. Determine specific heat capacity of ice.(Take specific heat capacity of water = 4200J/kg/k, specific latent heat of fusion of ice = 340,00J/kg and specific heat capacity of copper = 390J/kg/k)
Date posted: September 30, 2019.
- In an experiment to analyze a 200cm3 sample of air was treated with pyrogallic acid. This reduced its volume to 168cm3. Potassium hydroxide was then...(Solved)
In an experiment to analyze a 200cm3 sample of air was treated with pyrogallic acid. This reduced its volume to 168cm3. Potassium hydroxide was then added and the volume of gas reduced further to 160cm3.
(a) What was the role of pyrogallic acid?
(b) What was the role of potassium hydroxide?
(c) Calculate the percentage of oxygen and percentage of carbon (iv) oxide in the sample
(d) Suggest the likely biological source of carbon (iv)oxide gas.
(e) State the behavior of external intercostal muscles during exhalation.
(f) Explain why smokers are more prone to respiratory tract infections than the non- smokers
Date posted: September 30, 2019.
- The following diagram shows a cell at a certain stage of cell division.(Solved)
The following diagram shows a cell at a certain stage of cell division.
a) Name the type and stage of cell division.
Type
Stage
(b) (i) Give one reason for your answer in (a) above
(ii) What is the significance of the process shown in the diagram above in relation to the
behavior of chromosomes?
(c) What is the general name of organs where the above process occurs?
(d) Name the part labeled;
C
F
(e) State the significance of part labeled A in relation to the process shown above ?
(f) Name one cell in plants which is haploid
Date posted: September 30, 2019.
- The diagram below represents a nitrogen cycle. (a) Name the groups of organism represented by J.....(Solved)
The diagram below represents a nitrogen cycle.
(a) Name the groups of organism represented by J.
(b) Name the process represented by R,P,M and N.
(c) Name one process represented by T.
(d) (i) Name a structure in roots involved in process M.
(ii) State one adaptation of the structure named in d (i) above to its function
Date posted: September 30, 2019.
- The figure below shows two cars A and B moving in opposite direction along a straight road. The diagram shows their respective positions at equal...(Solved)
The figure below shows two cars A and B moving in opposite direction along a straight road. The diagram shows their respective positions at equal time intervals before the crush until the cars collided at point M. The diagram is drawn to scale of 1:10
i) Explain which driver had anticipated the collision.
ii) If the time between all the intervals was 0.5 seconds.
I. Determine the velocities Vp, VQ and VR
II. Car A had a mass of 8000kg while B had a mass of 1200kg. The cars coellesced and moved together a distance of 8m before coming to rest.
Determine:
I. The velocity after collision.
II.The common acceleration
Date posted: September 30, 2019.
- The diagram below shows a stage of a certain type of cell division.(Solved)
The diagram below shows a stage of a certain type of cell division.
a) Identify the stage and type of the cell division the above cell is undergoing.
b) State two importance of the above type of cell division
Date posted: September 30, 2019.
- In a capture-recapture exercise to estimate population size of dragon flies on a stretch of rivers, 250flies were first caught and marked. Two days later...(Solved)
In a capture-recapture exercise to estimate population size of dragon flies on a stretch of rivers, 250flies were first caught and marked. Two days later 500 flies were caught in the second capture and out of this, 50 flies had marks on their bodies. Estimate the population size of the flies. (show your working)
Date posted: September 30, 2019.
- The figure below shows a turn table, centre O with a mass of 30g at a distance of 6cm from the centre.(Solved)
The figure below shows a turn table, centre O with a mass of 30g at a distance of 6cm from the centre.
i) Determine the normal reaction between the 30g mass and the table. (2 marks)
ii) The 30g mass just slides off the table when the turn table rotates at a frequency of 1 revolution per second. Determine:
I. The angular velocity.
II. The coefficient of friction between the 30g mass and the table.
iii) Oil is poured on the table and the table is made to rotate at the same frequency of 1 revolution per second. On the figure,mark a point P along line OB where the 30g mass will just slide off.
Date posted: September 30, 2019.
- Explain the following Phenomena “Stomata generally open during the day and close at night”.(Solved)
Explain the following Phenomena “Stomata generally open during the day and close at night”.
Date posted: September 30, 2019.
- State four behavioural pattern or activities shown by terrestrial animals to their adaptations in habitats.(Solved)
State four behavioural pattern or activities shown by terrestrial animals to their adaptations in habitats.
Date posted: September 30, 2019.
- Pregnancy would persist after the expiry of the fifth month of pregnancy even if the two ovaries are surgically removed from the body of female...(Solved)
Pregnancy would persist after the expiry of the fifth month of pregnancy even if the two ovaries are surgically removed from the body of female individual. Give an account for this.
Date posted: September 30, 2019.
- State the adaptive structural differences between nephrons of desert and fresh water animals.(Solved)
State the adaptive structural differences between nephrons of desert and fresh water animals.
Date posted: September 30, 2019.
- During cold weather, very small mammals eat more than their own weight of food per day whereas large mammals eat food which is only a...(Solved)
During cold weather, very small mammals eat more than their own weight of food per day whereas large mammals eat food which is only a small fraction of their weight. Give an explanation for this.
Date posted: September 30, 2019.
- State the advantage of breeding seasons in Mammals other than Man?(Solved)
State the advantage of breeding seasons in Mammals other than Man?
Date posted: September 30, 2019.
- State the function of interstitial cells found in testis.(Solved)
State the function of interstitial cells found in testis.
Date posted: September 30, 2019.
- During a surgical operation, a doctor accidentally cut two blood vessels A and B. Out of blood vessel A, blood was spurting out while through...(Solved)
During a surgical operation, a doctor accidentally cut two blood vessels A and B. Out of blood vessel A, blood was spurting out while through blood vessel B, blood was flowing smoothly.
i) Identify blood vessels A and B.
Date posted: September 30, 2019.
- Name one hormone which promotes spermatogenesis in human males.(Solved)
Name one hormone which promotes spermatogenesis in human males.
Date posted: September 30, 2019.
- Give the role of the following hormones during menstrual cycle.
a) Follicle stimulating hormone.
b) Oestrogen.
c) Luteinizing hormone.(Solved)
Give the role of the following hormones during menstrual cycle.
a) Follicle stimulating hormone.
b) Oestrogen.
c) Luteinizing hormone.
Date posted: September 30, 2019.
- The table below shows the changes brought by hormones during reproduction in human females. Fill in the table.
(Solved)
The table below shows the changes brought by hormones during reproduction in human females. Fill in the table.
Date posted: September 30, 2019.
- A student examining pond water came across a certain living organisms which he drew as shown below.(Solved)
A student examining pond water came across a certain living organisms which he drew as shown below.
i) Identify the organism shown above.
ii) State the kingdom of the above organism.
iii) Name the structure labeled A.
iv) State the function of the part labeled B.
Date posted: September 30, 2019.