Large transformers, when used for some time, become very hot and are cooled by circulating oil. The heating of the transformer is due to

A. the heating effect of current alone

B. hysteresis loss alone

C. both the heating effect of current and hysteresis loss

D. intense sunlight at noon

Grade 9 science electricity:

Part B: True or False (K – 13 marks)

23. ______ Static electricity refers to electric charges that flow through a conductor in a controlled way.

24. ______ Lightning is an example of an electric current that is not controlled.

25. ______ Electrons move from the positive to the negative terminal of a battery in a circuit.

26. ______ A cell phone battery is an example of a secondary cell.

27. ______ If a switch is open in a series circuit, the circuit is complete and electrons are flowing.

28. ______ Wall outlets provide direct current.

29. ______ The difference in electric potential energy measured at two different points in a circuit is called current.

30. ______ Copper has a high electrical resistance.

31. ______ The lower the voltage of the source, the higher the current.

32. ______ The energy of electrons in a circuit decreases after they pass through the source.

33. ______ The cables that carry electricity from the generating station to your home are larger so that they can carry more current without heating up.

34. ______ Some appliances, like stoves, need to be connected to a higher voltage (240 Volt) circuit.

35. ______ Appliances that have failed to meet the government’s standards for electrical efficiency are given the Energy Star label.

Grade 9 Science – Lab Safety & Equipment Woksheet

Part A: Highlight ‘T’ for TRUE OR ‘F’ for FALSE for each of the following questions. (K - 35)

1. T F Broken glassware should be swept up immediately and placed in the garbage bin.
2. T F Eyeglasses or contact lenses are an acceptable substitute for googles during an experiment.
3. T F If you arrive at class to find a spilled liquid on your desk, you should assume it is water and wipe
 it up with paper towels.
4. T F Students with long hair must tie it back when using Bunsen burners.
5. T F If you take too much of the chemicals needed for an experiment, put it back into the container you
 got it from.
6. T F Class B fires are those related to electrical equipment.
7. T F Discard all solid waste by rinsing it down the sink.
8. T F You may consume food and drinks during a lab, as long as it is kept at a safe distance from
 chemicals.
9. T F If asked to detect the odour of a chemical in the lab, the student should inhale a deep breath of the
 chemical.
10. T F If your clothing were to catch on fire, your first step should be to STOP, DROP and ROLL.
11. T F When using a fire extinguisher, aim at the top of the fire. The chemical in the extinguisher will
 fall and put out the flames.
12. T F When heating chemicals in a test tube, heat from the bottom up, aiming the test tube at the
 ceiling, and keep the test tube still.
13. T F It is ok to take off my safety goggles if it’s just for a second while I write something down.
14. T F If any chemical makes contact with your eye, wash it immediately at the eyewash station for
 fifteen minutes. If you should spill chemicals on your skin, place the affected area under water
 immediately.
15. T F Always read through each activity before you begin.
16. T F If you are unsure about any part of the procedure for an experiment, you should figure it out
 yourself. Asking the teacher for clarification will result in a lower mark due to lack of preparation.
17. T F It is acceptable to sit during very long experiments.
18. T F It is ok if I don’t know where the lab safety equipment is since I can just ask someone later.
19. T F Be sure to tell your teacher about any accident, broken equipment, or injury that occurs during
 class; no matter how minor.
20. T F When working with chemicals, keep pens and pencils away from your mouth.
21. T F In warmer months, it is acceptable to wear sandals during an experiment.
22. T F Determine whether your equipment is cool enough to disassemble by placing the back of your
 hand near it.
23. T F Loose-fitting, long-sleeved shirts should be worn during experiments to protect your arms from
 burns and chemical splashes.
24. T F If you must retrieve materials during a lab, it is acceptable to leave your Bunsen burner unattended
 as long as it is set to a yellow flame.
25. T F To avoid an injury when heating materials, always place a stopper or tight-fitting lid on the
 container being heated.
26. T F If a student uses the last of the chemicals in an experiment, it is their responsibility to go into the
 storeroom to retrieve an additional quantity of that chemical.
27. T F Always leave your work area clean and dry before leaving the lab and make sure equipment and
 glassware is returned clean to its proper place.
28. T F Horseplay is O.K. during a lab as long as no one is getting hurt.
29. T F It is never advisable to place a thermometer in an open flame.
30. T F To cool hot glassware, run cold water over it.
31. T F Class A fires can be extinguished with water.
32. T F Class D fires must be extinguished with water.
33. T F Keep equipment away from the edge of the lab bench.
34. T F If your eye itches while you are working with chemicals, you should rub it with your hands.
35. T F WHMIS stands for warning hazardous materials information symbols.

Grade 9 Science electricity multiple choice:

1. All of the following are examples of a load in an electric circuit, except…
2. heaters b. motors c. lamps d. batteries

1. A continuous path in which electrons can flow is called a(n)…
2. electric circuit b. photovoltaic cell c. electric cell d. electrolyte

1. The part of an electric circuit that converts electrical energy into other forms of energy is called a(n)…
2. connecting wire b. energy source c. load d. switch

1. What type of energy does a fan convert into motion?light energy b. thermal energy c. electrical energy d. none of the above

1. An electric cell that may only be used once is called a… a. primary cell secondary cell c. fuel cell d. photovoltaic cell

1. Electrons will only flow in an electrical circuit if …
2. the circuit breaker is open. c. their path is complete and continuous
3. there is a gap between the conductors d. the switch is not closed.

1. The rate at which electric charges (electrons) move past a given point in a circuit is called…
2. voltage b. resistance c. current d. none of the above

1. The symbol for electric current is…
2. I b. V c. A d. C

1. A device used to measure potential difference is called a(n)…
2. electroscope b. ohmmeter c. ammeter d. voltmeter

1. Electrical resistance is measured in…

      a. amperes b. watts c. ohms d. volts

1. Electrical Resistance is the ability (or force) that …
2. stops or slows down the electric charges in a circuit        
3. that can either help or stop the electric charges in a circuit
4. helps or speeds up the electric charges in a circuit        
5. none of these are correct

1. Loads connected in series…
2. do not affect the total resistance of the circuit       c. increase the total resistance of the circuit
3. decrease the total resistance of the circuit       d. It depends on the wattage of the loads

1. What will happen to other lamps on a parallel circuit if an additional light bulb is added?
2. They will continue to glow the same brightness               c. Some will get brighter and some will go out
3. They will all continue to glow and will get brighter            d. They will all go out

1. A series circuit has three identical lamps. The potential difference of the energy source is 30V. The resistance of each lamp is 5 Ω. What is the current through each lamp? (Hint: draw a picture of the circuit)

1. 0.167 A b. 2 A c. 6 A d. 150 A

1. One watt of electrical power is equal to…
2. one joule per second       b. one joule per minute   c. ten joules per second d. ten joules per minute

1. Electrical energy in your home is measured in…
2. Joules       b. Amps       c. Kilowatt-Hours     d. Watts

1. If you wish to lower your energy costs, which of the following times would be best to use an electric clothes dryer?
2. Monday at 1:00 p.m.   b. Tuesday at 9:00 a.m. c. Friday at 3:00 p.m.             d. Saturday at 8:00 p.m.

1. An older electrical safety device that contains a small wire that melts and breaks apart when current is too high is a…
2. Circuit Breaker       b. Fuse       c. Ground Fault Interrupter       d. 3-hole outlet

1. This electrical safety device, which is typically found in bathrooms, sc

1. Circuit Breaker       b. Fuse       c. Ground Fault Interrupter     d. 3-hole outlet

1. Which of the following devices measures the amount of energy used every hour in a house or apartment building?
2. Phantom load       b. Fuse               c. Smart Meter         d. Ground Fault Interrupter