3_5 DC Sources of Electricity

A 20 cell battery with each cell having an internal resistance of 0.1 ohms is charged with 2 leads having a total resistance of 0.1 ohms. The battery is charged with a current of 5 amps. What is the charging voltage ?

• 0.5 volts

• 10.5 volts

• 0.005 volts

Two 10V, 20 Ah batteries are connected in parallel and connected across a 10 ohm load. How long could they supply normal current before the voltage begins to decay?

• 40 hours

• 20 hours

• 4 hours

A battery rated at 40 Ah will supply 200 mA for.

• 200 hours

• 20 hours

• 5 hours

A zinc-carbon battery life depends upon.

• the amount of zinc

• the purity of the carbon rod

• the amount of the electrolyte paste

When checking the SG of the electrolyte in a lead acid battery, you should.

• check any cell because they will all be the same

• check only the no. 1 cell because it is the master cell

• check all cells because they may be different

The PD at the terminals of an open circuit battery with a small internal resistance will be.

• more than the EMF

• less than the EMF

• the same as the EMF

An accumulation of hydrogen on the plates of a battery is known as.

• polarization

• ionization

• hydration

What part of a battery is covered in hydrogen during polarization?

• Anode

• Both the anode and the cathode

• Cathode

Which of the following is most likely to cause thermal runaway in a nickel-cadmium battery?

• A high internal resistance condition

• High current charging of the battery to more than 100 percent of its capacity

• Excessive current draw from the battery

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

• the voltage with rated load switched ON

• the voltage on open circuit

• the voltage off load