A 100% efficient step-down transformer decreases the voltage of an alternating current (a.c.) electricity supply. What effect does this step-down transformer have on the mean power transferred and the alternating…
The diagram shows the suggested changes in energy labelled as a, b, c, d and e, during a chemical change from reactants to products. Which value is the correct energy…
Which row identifies what is occurring during anaerobic respiration in animal cells? Answer: 5) A The respiration is ANAEROBIC, meaning no oxygen is used.Carbon dioxide is only formed in aerobic…
A bag contains only 8 beads. The beads are identical in all respects except colour. 3 of the beads are black and the other 5 beads are white. A bead…
The colour of the surface of an object has an effect on the rate of infrared radiation that it absorbs and emits. As a result of this, some clothes which…
Which of the following organic compounds will decolourise bromine water by reacting with it at room temperature? Answer: 2) C Only alkenes are the organic compounds which turn orange-brown bromine…
Which one of the following is not part of a reflex to the stimulus of placing your hand on a hot object? Answer: 1) E The brain is not involved…