Science Quiz 2010 SECONDARY LEVEL 4th Year Prof. Jasmine Angelie V. Albelda

MECHANICS 1.The quiz consists of three rounds: Easy, Average and Difficult. There are 10 questions in the Easy Round and 5 questions for the Average and Difficult Rounds. 2.Each correct answer in the Easy, Average and Difficult round merits one point (1), two points (2) and three points (3) respectively. At the end of all rounds, the scores of each contestant will be added to determine the winners. 3.Misspelled answers are considered incorrect. There are no deductions for wrong answers. 4.For items requiring computations, rules of significant figures apply in the final answer.

MECHANICS 4. The judge shall read each question ONCE. The allotted time shall start when the reading is done. 5.All complaints must be raised immediately before the next question is asked. Complaints must be addressed only to the board of judges. The decision of the board of judges is final and irrevocable. 6.In case of a tie, a sudden death question will be asked. The contestant who can give the correct answer will be proclaimed the winner.

EASY Round

EASY – 1 10 s The diagram shows a patient having her eyes tested. A chart with letters on it is placed behind her and she sees the chart reflected in a plane mirror. How far away from the patient is the image of the chart? Answer :7 m

EASY – 2 10 s Answer :A Why is electrical energy usually transmitted at high voltage? A.So that the current in the transmission cables is as small as possible. B.So that the current in the transmission cables is as large as possible C.So that the resistance of the transmission cables is as small as possible. D.So that the resistance of the transmission cables is as large as possible

EASY – 3 15 s Three identical metal bars P,Q and R are suspected of being magnets. Tests are carried out and it is found that there is attraction between poles 1 and 6, between 2 and 4 and between 2 and 6. However, there is repulsion between poles 2 and 3. Answer :P and Q 1 2 P 3 4 Q 5 6 R Without making any further tests, which of the metal bars is/are magnets?

EASY – 4 10 s A man who is standing at point X between two parallel walls fires a pistol. He hears echoes after 0.5 s and 0.8 s. At what time would a further echo be heard? Assume that the speed of sound in air is 340 m/s. Answer :1.3 s X

EASY – 5 20 s Which of the following electromagnets would give the desired magnet? Answer : C It is desired to produce a magnet that is shown on the right

EASY – 6 10 s A 1.5 V, AAA cell supplies 750 mA of current through a flashlight bulb for 5.0 minutes, while a 1.5 V, C cell supplies 750 mA of current through the same flashlight bulb for 20 minutes. Compared to the total charge transferred by the AAA cell through the bulb, the total charge transferred by the C cell through the bulb is: A. half as great B. the same C. twice as great D. four times as great Answer :D

EASY – 7 10 s When green light travels from water to air, what are the changes, if any, to its velocity, frequency and wavelength? Answer :D VelocityFrequencyWavelength AUnchangedIncreasedDecreased BUnchangedDecreasedIncreased CDecreasedUnchangedDecreased DIncreasedUnchangedIncreased

EASY – 8 10 s A steel ball is falling at a constant speed in oil. Which of the following graphs show the variation with time of the gravitational potential energy E p and the kinetic energy E k of the ball? Answer : B

EASY – 9 10 s A student sets up a model transformer as shown on the right. Answer : A Lamp PLamp Q A Normal brightness Not lit B Very brightDim C Normal brightness Very bright D DimVery bright The coil is connected to a 2.5 V supply. Both lamps have a voltage of 2.5 V. When the circuit is closed, which of the following is observed by the student about the lamps?

EASY – s Three small beads of the same mass rolls down the following frictionless tracks A, B and C. Answer :II, III and IV Which of the following statements is/are true about the acceleration of the beads? I.The acceleration of the bead in tracks A, B and C are the same II.The acceleration of the bead in track A is constant III.The acceleration of the bead in track B is decreasing IV.The acceleration of the bead in track C is increasing AB C