IBPhysics 11.3 Capacitance: Q=CV, Energy, Adding Capacitance

Which is the correct relationship between capacitance (C), charge stored on the capacitor (Q) and the potential difference across the capacitor (V)?

• $Q=CV$

• $C=QV$

• $V=QC$
  

• $Q=\frac{CV^2}{2}$

• $Q=\frac{CV}{2}$

What is the unit of capacitance?

• ohm, Ω

• Farad, F

• Henry, H

• Tesla, T

A simple capacitor of capacitance C is produced using 2 parallel plates of area, A, and separation, d. (Air is used as the dielectric material).

If the separation of the plates is halved to d/2 and the area of both plates is doubled, what is the new capacitance?

• $\frac{C}{4}$

• $\frac{C}{2}$
  

• $4C$
  

• $2C$
  

Capacitors are made using 'dielectric materials'. Which of these statements best describes a dielectric material?

• A conductor that can be polarised.

• A conductor that can't be polarised.

• An insulator that can't be polarised.

• An insulator that can be polarised.

A 0.01 mF capacitor is connected to a 10 V cell. Calculate the charge stored on the capacitor.

• 0.1 F

• 0.1 C

• 0.1 mC

• 0.1 C

A 0.01 mF capacitor is connected to a 10 V cell. Calculate the energy stored on the capacitor.

• 0.5 J

• 0.5 mJ

• 0.1 J

• 1.0 mJ

Calculate the total capacitance in circuit A, where each capacitor is identical and has capacitance of 100 pF.

• 200 pF

• 100 pF

• 50 pF

• 67 pF

Calculate the total capacitance in circuit B, where each capacitor is identical and has capacitance of 100 pF.

• 200 pF

• 100 pF

• 50 pF

• 67 pF

Calculate the total capacitance in circuit C, where each capacitor is identical and has capacitance of 100 pF.

• 200 pF

• 100 pF

• 50 pF

• 67 pF