3.5 - DC Sources of Electricity Flashcards

1
Q
  1. The electrolyte in a lead acid battery consist of;
    (a) Sulphuric acid and water.
    (b) Boric acid and water.
    (c) Hydrochloric acid and water.
A

(a) Sulphuric acid and water.

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2
Q
  1. Three batteries are connected in parallel to form a power supply each battery
    produces 8 Volt and have a capacity of 4 A/Hs. The total power supply voltage and
    capacity is;
    (a) 8Vand12A/H
    (b) 24V and 4 A/H.
    (c) 24Vand12A/H.
A

(a) 8Vand12A/H

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3
Q
  1. Which of the following is the purpose of an electrical cell?
    (a) To change mechanical energy to electrical energy
    (b) To change chemical energy to electrical energy
    (c) To change electrical energy to mechanical energy
    (d) To change electrical energy to chemical energy
A

(b) To change chemical energy to electrical energy

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4
Q
  1. The liquid used in cells to produce voltage by chemical action is called?
    (a) electrolyte
    (b) alcohol
    (c) lubricant
A

(a) electrolyte

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5
Q
  1. With respect to recharging a primary or secondary cell, of the following
    statements, which one is correct?
    (a) The secondary cell can be recharged by passing current through it in the proper
    direction
    (b) The primary cell can be recharged by passing current through it in the proper
    direction
    (c) The secondary cell can only be recharged by changing the electrodes
    (d) The primary cell can only be recharged by changing the electrolyte
A

(a) The secondary cell can be recharged by passing current through it in the proper
direction

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6
Q
  1. Which of the following actions will recharge a secondary cell?
    (a) Adding more water to the electrolyte
    (b) Adding more active ingredient to the electrolyte
    (c) Connecting the negative terminal of a voltage source to the cathode of the cell and
    the positive terminal of the voltage source to the anode of the cell
    (d) Connecting the negative terminal of a voltage source to the anode of the cell and
    the positive terminal of the voltage source to the cathode of the cell
A

(c) Connecting the negative terminal of a voltage source to the cathode of the cell and
the positive terminal of the voltage source to the anode of the cell

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7
Q
  1. What determines the amount of current which will flow through a battery while it is
    being charged by a constant voltage charger?
    (a) the number of cells in the battery
    (b) the state of charge of the battery
    (c) the ampere-hour capacity of the battery
A

(b) the state of charge of the battery

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8
Q
  1. A fully charged Lead-Acid battery will not freeze until extremely low temperatures
    are reached because:
    (a) The acid is in the plates, therby increasing the specific gravity of the solution
    (b) Most of the acid is in the solution
    (c) All the water in rhe solution is absorbed by the plates
A

(b) Most of the acid is in the solution

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9
Q
  1. A battery with a capacity of 600 ampere-hours should provide 3 amperes for a
    maximum of how many hours?
    (a) 100 hr
    (b) 200 hr
    (c) 300 hr
    (d) 600 hr
A

(b) 200 hr

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10
Q
  1. A battery is rated according to a 20-hour rate of discharge at 300 ampere-hours.
    Which of the following currents is the maximum current that will allow the battery to
    deliver its rated capacity?
    (a) 15 amperes
    (b) 20 amperes
    (c) 25 amperes
    (d) 30 amperes
A

(a) 15 amperes

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11
Q
  1. A 20 Amps load is place on a battery and after 48 minutes the battery is
    considered fully discharged. The battery has a nominal rate of 20AH at the 1 hour
    rate what is its capacity.
    (a) 70%
    (b) 80%
    (c) 90%
A

(b) 80%

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12
Q
  1. What would you used to neutralize a spillage from a Lead AcidBattery.
    (a) Sodium Bicarbonate
    (b) Sulphuric crystals,
    (c) Boric Acid
A

(a) Sodium Bicarbonate

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13
Q
  1. An accumulation of hydrogen on the plates of a battery is known as
    (a) hydration
    (b) polarization
    (c) ionization
A

(b) polarization

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14
Q
  1. The method of ascertaining the voltage of a standard aircraft lead-acid battery is
    by checking
    (a) the voltage on open circuit
    (b) the voltage with rated load switched ON
    (c) the voltage off load
A

(b) the voltage with rated load switched ON

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15
Q
  1. The NiCad cell gas barrier separator can be damaged by:
    (a) overcharging
    (b) using constant current charging
    (c) leaving it in a discharged state
A

(a) overcharging

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16
Q
  1. In a voltaic cell, what is the build-up on the cathode called?
    (a) Polarization
    (b) Sulphation
    (c) Hydration
A

(a) Polarization

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17
Q
  1. If a battery has got low internal resistance, then
    (a) on load voltage will be greater than no load voltage
    (b) no load voltage will be greater than on load voltage
    (c) no load voltage will be the same as on load voltage
A

(b) no load voltage will be greater than on load voltage

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18
Q
  1. If, during the charge of a Lead-Acid battery the current was not adjusted, it would
    (a) Decrease
    (b) Increase
    (c) Remain constant.
A

(a) Decrease

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19
Q
  1. When the battery voltage is higher than the battery charger voltage:
    (a) The battery will discharge through the charger
    (b) The charger will charge the battery
    (c) No current will flow between the two.
A

(c) No current will flow between the two.

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20
Q
  1. When the battery voltage is lower than the battery charger voltage:
    (a) The battery will discharge through the charger
    (b) The charger will charge the battery
    (c) No current will flow between the two.
A

(b) The charger will charge the battery

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21
Q
  1. The resistance of a battery terminals:
    (a) should be as high as possible
    (b) reduces the output voltage
    (c) has no effect on the output voltage
A

(b) reduces the output voltage

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22
Q
  1. Two batteries 12V and 40 Ah each, are in series. What is the total capacity?
    (a) 12V 80 Ah
    (b) 24V 80Ah
    (c) 24V 40 Ah
A

(c) 24V 40 Ah

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23
Q
  1. Which of the following is most likely to cause thermal runaway in a nickelcadmium battery
    (a) excessive current draw from the battery
    (b) high current charging of the battery to more than 100 percent of its capacity
    (c) a high internal resistance condition
A

(b) high current charging of the battery to more than 100 percent of its capacity

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24
Q
  1. During a battery load check the voltage is expected to:
    (a) fall slightly
    (b) rise slightly
    (c) remain constant
A

(a) fall slightly

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25
Q

What is a battery?

A

A battery is a device containing either a single cell or combination of cells to convert chemical to electrical energy

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26
Q

According to the Law, a battery must supply power to an aircraft in the event of an emergency for how long?

A

minimum 30 minutes

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27
Q

The electrodes on a battery must be made of?
(a) The same metal
(b) Different metals
(c) It doesn’t really matter

A

(b) Different metals

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28
Q

The liquid used in cells to produce voltage by chemical action is called?
(a) electrolyte
(b) alcohol
(c) lubricant

A

(a) electrolyte

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29
Q

The POSITIVE electrode on a battery is properly called the?
(a) Anode
(b) Cathode
(c) Electrode

A

(b) Cathode

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30
Q

Which one of these substances when mixed in water would NOT make a good electrolyte?
(a) Acid
(b) Oil
(c) Alkaline
(d) Salt

A

(b) Oil

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31
Q

For the electrolyte in a battery to effectively operate, it must contain?
(a) Covalent bonds
(b)Pure water only
(c) Ions

A

(c) Ions

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32
Q

What do we call the process that goes on inside the battery?

A

electrochemical action

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33
Q

Which of the following is the purpose of an electrical cell?
(a) To change mechanical energy to electrical energy
(b) To change chemical energy to electrical energy
(c) To change electrical energy to chemical energy

A

(b) To change chemical energy to electrical energy

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34
Q

With respect to recharging a primary or secondary cell, of the following statements, which one is correct?
(a)The secondary cell can be recharged by passing current through it in the proper direction
(b)The primary cell can be recharged by passing current through it in the proper direction
(c)The secondary cell can only be recharged by changing the electrodes

A

(a)The secondary cell can be recharged by passing current through it in the proper direction

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35
Q

If a battery has got substantial internal resistance, then the:
(a)on load voltage will be greater than no load voltage
(b)no load voltage will be greater than on load voltage
(c)no load voltage will be the same as on load voltage

A

(b)no load voltage will be greater than on load voltage

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36
Q

The resistance of a battery terminals:
(a) should be as high as possible
(b) reduces the output voltage
(c) has no effect on the output voltage

A

(b) reduces the output voltage

37
Q

A battery is rated according to a 20-hour rate of
discharge at 300 ampere-hours. Which of the following
currents is the maximum current that will allow the
battery to deliver its rated capacity?
(a) 15 amperes
(b) 20 amperes
(d) 30 amperes

A

(a) 15 amperes

38
Q

If a battery capacity is rated at 7 Ahr , then how many Coulombs of charge could be available?
(a) 420 Coulombs
(b) 25,200 Coulombs
(c) 7 Coulombs

A

(b) 25,200 Coulombs

1A = 1 Coulomb/second
7A = 7 C/s
convert s to hrs and you get 25200

39
Q

Two batteries 12V and 40 Ah each, are in series. What is the total capacity?
(a) 12V 80 Ah
(b) 24V 80Ah
(c) 24V 40 Ah

A

(c) 24V 40 Ah

Note: Batteries in seres increase voltage like pumps in series. Example, If a pump of 1.5 psi is connected to another pump of 1.5 psi, total output is 3 psi as second pump has to create differential of 1.5 psi starting already from 1.5 so final output is 3 psi

40
Q

Three batteries are connected in parallel to form a power supply each battery produces 8 Volt and have a capacity of 4 AHr. The total power supply voltage and capacity is;
(a) 8Vand12AHr
(b) 24V and 4 AHr.
(c) 24Vand12AHr.

A

(a) 8Vand12AHr

41
Q

During a battery load check the voltage is expected to:
(a) fall slightly
(b) rise slightly
(c) remain constant

A

(a) fall slightly

42
Q

The process that takes place in a battery is called?
(a) Electrostatic Action
(b) Electromatic Action
(c) Electrochemical action

A

(c) Electrochemical action

43
Q

The anode of a Lead Acid cell is made of?
(a) Lead Oxide
(b) Spongy Lead
(c) Zinc

A

(b) Spongy Lead

44
Q

The electrolyte in a lead acid battery consist of;
(a) Sulphuric acid and water.
(b) Boric acid and water.
(c) Hydrochloric acid and water.

A

(a) Sulphuric acid and water.

45
Q

How many cells are ther in a 24VDC Lead-Acid Battery?
(a) 20
(b) 12
(c) 24

A

(b) 12

46
Q

In a cell, what is the Hydrogen gas build-up on the electrode called?
(a) Polarization
(b) Sulphation
(c) Hydration

A

(a) Polarization

47
Q

Which one of these actions CANNOT reduce Polarization on electrodes?
(a) Making the electrode porous
(b) Adding more electrolyte
(c) Adding manganese dioxide to the electrode alloy

A

(b) Adding more electrolyte

48
Q

When a Lead Acid battery is fully discharged?
(a) Only the Anode has lead-sulphate attached to it.
(b) Only the Cathode has lead-sulphate attached to it.
(c) Both the electrodes have lead-sulphate attached to them.

A

(c) Both the electrodes have lead-sulphate attached to them.

49
Q

Which of the following actions will recharge a secondary cell?
(a) Adding more water to the electrolyte
(b) Connecting the negative terminal of a voltage source to the cathode of the cell and the positive terminal of the voltage source to the anode of the cell
(c) Connecting the negative terminal of a voltage source to the anode of the cell and the positive terminal of the voltage source to the cathode of the cell

A

(c) Connecting the negative terminal of a voltage source to the anode of the cell and the positive terminal of the voltage source to the cathode of the cell

50
Q

A fully charged Lead-Acid battery will not freeze until extremely low temperatures are reached because:
(a)The acid is in the plates, thereby increasing the specific gravity of the solution
(b)Most of the acid is in the solution
(c)All the water in the solution is absorbed by the plates

A

(b)Most of the acid is in the solution

51
Q

In a fully discharged Lead Acid battery the amount of acid in the water is at its?
(a) Highest
(b) Lowest
(c) It never changes

A

(b) Lowest

52
Q

The specific gravity of a fully charged lead-acid battery would be approximately?
(a) 1.150
(b) 1.000
(c) 1.280

A

(c) 1.280

53
Q

“Local Action” takes place in battery?
(a) Only when its charging
(b) Only when its discharging
(c) At all times (even when in storage)

A

(c) At all times (even when in storage)

54
Q
A

C. Potassium hydroxide

55
Q
A

C. To disable the charger in cases of thermal runaway

56
Q
A

B. Empty all the current charge out and then place a controlled flow in

57
Q
A

B. 15 C

58
Q
A

C. Upwards

59
Q
A

B. NiCad batteries

60
Q
A

C. Fall over time

61
Q
A

C. Its voltage must be more than the batterys

62
Q
A

A. Yes

63
Q
A

B. 30 min

64
Q
A

A. Lead-acid batteries

65
Q
A

C. Acetic or boric acid (vinegar)

66
Q
A

A. Baking soda

67
Q
A

(b) the voltage with the rated load switched ON

68
Q
A

(a) Zinc

69
Q
A

(b) Carbon

70
Q
A

(c) Ammonium Chloride

71
Q
A

(a) Potassium Hydroxide

72
Q
A

(b) Contain a ‘‘moist paste’’ inside

73
Q
A

(a) Wet Cell

74
Q
A

(b) the state of charge of the battery

75
Q
A

(c) No current will flow between the two

(There is usually a Diode in the charge)

76
Q
A

(c) Seconday Cell

77
Q
A

(b) high current charging of the battery to more than 100 percent of its capacity

78
Q
A

(a) 15V and 12A/H

79
Q
A

(b) the state of charge of the battery

80
Q
A

(b) 80%

20 Amps / 48 mins
(60)(20) Amps / 48 hours
(12)(5) * (5)(4) Amps / (12)(4) hours
25 Amps / hours pr 25AH … Therefore if at 1 hour battery is 20AH charged, 4/5 of capacity (25) so 80%

81
Q
  1. The electrolyte in a lead acid battery consist of;
    (a) Sulphuric acid and water.
    (b) Boric acid and water.
    (c) Hydrochloric acid and water.
A

(a) Sulphuric acid and water.

82
Q
  1. Which of the following actions will recharge a secondary cell?

(a) Adding more water to the electrolyte
(b) Adding more active ingredient to the electrolyte
(c) Connecting the negative terminal of a voltage source to the cathode of the cell and the
positive terminal of the voltage source to the anode of the cell
(d) Connecting the negative terminal of a voltage source to the anode of the cell and the
positive terminal of the voltage source to the cathode of the cell

A

(c) Connecting the negative terminal of a voltage source to the cathode of the cell and the
positive terminal of the voltage source to the anode of the cell

83
Q
  1. An accumulation of hydrogen on the plates of a battery is known as
    (a) hydration
    (b) polarization
    (c) ionization
A

(b) polarization

84
Q
  1. A battery is rated according to a 20-hour rate of discharge at 300 ampere-hours. Which of the
    following currents is the maximum current that will allow the battery to deliver its rated
    capacity?

(a) 15 amperes
(b) 20 amperes
(c) 25 amperes
(d) 30 amperes

A

(a) 15 amperes

85
Q
  1. What would you used to neutralize a spillage from a Lead AcidBattery.
    (a) Sodium Bicarbonate
    (b) Sulphuric crystals,
    (c) Boric Acid
A

(a) Sodium Bicarbonate (Baking soda)

86
Q
  1. When the battery voltage is lower than the battery charger voltage:

(a) The battery will discharge through the charger
(b) The charger will charge the battery
(c) No current will flow between the two.

A

(c) No current will flow between the two.

(Under review as surely answer is (b) the charger will charge the battery)

87
Q
  1. The method of ascertaining the voltage of a standard aircraft lead-acid battery is
    by checking

a. the voltage on open circuit
b. the voltage with rated load switched ON
c. the voltage off load

A

b. the voltage with rated load switched ON

88
Q
  1. If, during the charge of a Lead-Acid battery the current was not adjusted, it would
    a. Decrease
    b. Increase
    c. Remain constant.
A

a. Decrease

89
Q
  1. When the battery voltage is higher than the battery charger voltage:

a. The battery will discharge through the charger
b. The charger will charge the battery
c. No current will flow between the two.

A

c. No current will flow between the two.