This question is about the structure and operation of a parallel plate capacitor.

State what is meant by a capacitance of 370 $\mu$F.

A parallel plate capacitor is constructed from two metal plates separated by a dielectric with a dielectric constant of 5.

Explain what is meany by a dielectric constant of 5.

The dielectric is made up of polar molecules. 

Explain how the capacitance of the capacitor changes when the dielectric is inserted between the two metal plates.

A potential difference of 12 V is applied across the 370 $\mu$F capacitor.

Calculate the energy stored by the capacitor. Give your answer to 3 significant figures in mJ.

A parallel plate capacitor has two metal plates of area 200 cm³. A dielectric with relative permittivity 3.0 is inserted between the two metal plates. 

Calculate the capacitance of the capacitor when the metal plates are separated by a distance of 1.5 mm. Give your answer in pF.

The capacitor is connected to a 10 V power supply and charged. 

Calculate the energy stored by the capacitor when fully charged.

When the capacitor is fully charged the power supply is disconnected. 

The dielectric is then removed. 

Calculate the change in energy stored by the capacitor when the dielectric is removed.

Explain why the energy stored by the capacitor increases when the dielectric is removed.

A student is investigating the charging and discharging of behaviour of a capacitor. 

The circuit used by the student is in the diagram below.

The capacitor has a capacitance of 470 $\mu$F.

State what is meant by a capacitance of 470 $\mu$F.

The capacitor is initially uncharged.

Explain what happens when the student moves the switch to the position shown in the diagram.

The student records the potential difference across the capacitor every second until the capacitor is fully charged.

Identify the time constant from the graph and hence calculate the value of the resistor R.

When the capacitor is fully charged the potential difference across it is 10 V. 

The student moves the switch to position Y and the capacitor begins to discharge. 

Calculate the potential difference across the 2R resistor after 3 s.

A capacitor of capacitance 450 nF consists of two parallel metal plates separated by an insulator of thickness 1.7 mm. The area of overlap between the plates 350 cm².

Calculate the permittivity of the insulator between the capacitor plates.

The 450 nF capacitor is connected in series with a 4 k$\Omega$ resistor and a cell of emf 9 V. 

Calculate the time taken for the capacitor to charge by 50%.  

As the capacitor charges the current, potential difference and charge vary.

Sketch the shapes of the graphs for current, charge and potential difference as the capacitor charges.

A student is investigating the charging and discharging characteristics of a capacitor. 

Draw a voltmeter to measure the potential difference across the capacitor as it discharges.

The student records the voltage across the capacitor as it discharges. 

The table below shows the student's results.

Plot a graph of potential difference against time for the capacitor discharge.

Explain what is meant by the time constant and use the graph to identify the time constant for the capacitor discharge.

When the voltage across the capacitor is 4 V, it stores 1.2 x 10^-3 C.

Calculate the energy stored in the capacitor when fully charged to 10 V.

A student is investigating the capacitance of networks of capacitors.

Each capacitor in the network has a capacitance of 200 $\mu$F. 

Explain what is meant by a capacitance of 200 $\mu$F.

The capacitor network that the student uses is shown below.

Each capacitor has a capacitance of 200 $\mu$F.

Calculate the total capacitance of the network.

Initially the capacitor network is uncharged. 

When the power supply is connected the capacitors begin to charge.

Calculate the initial current through the resistor.

Calculate the potential difference across the resistor after 2.5 s.

A student is investigating the energy stored in a parallel plate capacitor.

The student uses a capacitor that is rated at 330 $\mu$F and 6 V.

Calculate the energy stored in the capacitor when fully charged.

The student charges the capacitor to 6 V before discharging it through a fixed resistor. 

The student records the potential difference across the capacitor as it discharges.

The student plots a graph of their results.

Calculate the value of the resistor used to discharge the capacitor. Give your answer to two significant figures.

The capacitor used had a relative permittivity of 3. 

The capacitor is charged and then disconnected from the power supply. The dielectric is then removed and replaced with a dielectric with a relative permittivity of 2.5.

Calculate the energy stored by the capacitor after the dielectric is swapped.

A student charges a 100 $\mu$F capacitor through a 2 k$\Omega$ resistor.   

State what is meant by the term time constant.

Calculate the time constant for the student's circuit.

Calculate the time it takes for the capacitor to charge to 75 % of the supply voltage.

When the capacitor is charged to 12 V, the power supply is disconnected. 

A 330 $\mu$F capacitor is connected in parallel such that the charge stored is shared evenly between both capacitors. 

Calculate the potential difference across the capacitor network. 

A capacitor is made from two metal plates of surface area 300 cm². A dielectric is placed between the plates with a dielectric constant of 4.5. The plates are separated by 1.4 mm. 

Calculate the capacitance of the capacitor.

The capacitor is charged through a 2 k$\Omega$ resistor. 

Calculate the time taken for the capacitor to charge to 50% of the supply voltage. 

When the capacitor is fully charged the power supply is disconnected. 

The dielectric is then removed. 

Explain how the energy stored by the capacitor changes when the dielectric is removed.

Capacitors are used in cameras to provide a short burst of current to a lamp for the camera flash.

The camera contains a 500 $\mu$F capacitor which discharges through the 450 $\Omega$ lamp.

When fully charged the capacitor has a potential difference of 9 V across the plates.

Calculate the time taken for the capacitor to discharge by 90%.

The duration of the camera flash can be modified by adding another 500 $\mu$F capacitor in series or parallel with the first.

Calculate the minimum time for the capacitor network to discharge by 90%.

The two capacitors are connected in parallel and charged to 9 V. 

Calculate the energy stored in the capacitor network.