In statistics Spearman’s rank correlation coefficient is given by the formula: Rearrange the formula to make ∑ 2 d the subject: Rearrange the formula to make ∑ 2 d the…

A force F is applied to the piston X of a brake pedal. This force is transmitted, hydraulically, to piston Y as shown in the diagram. Diameter of piston X…

A gene controls the production of chlorophyll in lettuce plants. The recessive allele of this gene blocks chlorophyll formation which prevents seedling development. Plants heterozygous for this gene were cross…

Which changes to the conditions will increase the yield of the salt in the exothermic reaction shown? Answer: 9) B Firstly, catalysts do not affect the equilibrium position and so,…

A health club monitors the average heart rate of its members when using a cardiovascular workout machine. The lower quartile of the heart rate is 115, the upper quartile is…

The following statements can be applied to certain types of wave:1 Their oscillations are longitudinal.2 They travel at the speed of light in air.3 They are used in pre-natal scanning.4…

The sides of triangle ABC are as follows: AB = 3, AC = 2, BC = 4. Use the cosine rule, a^2=b^2+c^2-2bc cosA , to find the cosine of ∠BAC…

Listed are the electronic configurations for the atoms of different elements. Which one represents the most reactive non-metal? Answer: 5) C As you go along a period, reactivity of non-metal…

The amount of water in urine is controlled by the hormone ADH. Which sequence of events will occur when you need to keep water in your body? Answer: 4) B…

A particular radioisotope X with a half-life of 4 years decays into the stable isotope Y. At a particular time, a sample contains 32 x 10²º atoms of nuclide X…