Capacitance

Capacitance is defined as _____

• p.d. per unit charge

• charge per unit p.d.

• p.d. per unit current

• current per unit p.d.

Two capacitors of capacitance 20 μF are connected in parallel. What is the combined capacitance?

• 10 μF

• 20 μF

• 30 μF

• 40 μF

Three capacitors of capacitances 20 nF, 30 nF and 60 nF are connected in series. What is the combined capacitance?

• 5 nF

• 10 nF

• 20 nF

• 110 nF

Two of the following arrangements of identical capacitors have the same combined capacitance. Which two?

• 
• 
• 
• 

A photoflash capacitor (used in flash camera) has a capacitance of 1700 μF and a maximum working voltage of 330 V. How much energy is stored when it is charged up to the working voltage?

• 185 J

• 93 J

• 0.56 J

• 0.28 J

A capacitor charged to 6 V stores 4 mJ of energy. If it is charged to 12 V, what is the energy stored (asuming it doesn't blow)?

• 4 mJ

• 8 mJ

• 16 mJ

• 48 mJ

A capacitor of capacitance 4700 μF can store a maximum charge of 0.1645 C. If ten such capacitors are connected in parallel to a battery of e.m.f. 36 V, will the capacitors blow?

• They will.

• They won't.