Which one of the following statements is true for an electrolytic capacitor?
It holds less charge than a non-electrolytic capacitor.
It does not conduct electricity if connected with reverse polarity.
It can explode if connected with reverse polarity.
It has a very high breakdown voltage.
The formula that relates charge, voltage, and capacitance is:
Q = C/V
Q = CV
Q = V/C
Q
= ½VC
A dielectric is:
A layer of insulating material between two plates of a capacitor.
A layer of conducting material between two plates of a capacitor.
The material from which the plates of the capacitor is made.
A slang term in the electronics industry for a fatal electric shock, especially from a capacitor charged to a high voltage
A capacitor is in series with a light bulb. When connected to a battery the bulb flashes momentarily then goes out. The reason for this observation is that:
The current has blown the filament of the bulb.
The current starts off at zero rapidly increasing to a high value.
The current starts off at a high value rapidly decreasing to zero.
The capacitor is faulty and has stopped conducting electricity.
The same capacitor and bulb as in Q 4 are now connected to an alternating current supply. The bulb glows. Which one of the statements is correct?
Charge is flowing on and off the plates, resulting in a current, which lights the bulb. The capacitor does NOT conduct electricity.
The capacitor has started to conduct electricity, so a current flows through the bulb.
The capacitor has turned the alternating current into direct current, enabling the bulb to glow.
The capacitor is faulty, so current is passing through it.
What charge is held by a 2.2 microfarad capacitor at a voltage of 6 V?
13.2
mC
2.2
mC
6.0
mC
0.33
mC
Which one of the following statements is true about the energy in a capacitor?
The formula is
E = QV and the energy is the area under the charge-voltage graph.
The formula is
E = ½ QV^{2} and the energy is the gradient of the charge-voltage graph.
The formula is
E =
½ QV
and the energy is the gradient of the charge-voltage graph.
The formula is
E =
½ QV and the energy is the area under the charge-voltage graph.
Which one of the following best describes what quantities decay exponentially when a capacitor is discharged?
Charge only
Charge and voltage only.
Current and charge only.
Current, voltage, and charge.
Which one of the following statements is correct about the
RC time constant?
It is measured in seconds and is the time taken for the voltage to drop to 50 % of its original value
It is measured in seconds and is the time taken for the voltage to drop to 37 % of its original value
It is measured in Hertz and is the time taken for the voltage to drop to 50 % of its original value
It is measured in Hertz and is the time taken for the voltage to drop to 37 % of its original value
Which one of the following actions will NOT change the half-life of an exponential decay?
Decreasing the value of the resistor.
Increasing the value of the capacitor.
Changing the original voltage to a higher value,
Replacing the resistor with a filament lamp whose cold resistance is the same value as the resistor.