11.3 Part 3

What will be the p.d. on the plates when they are fully charged?

• Same as emf of the battery.

• p.d. is shared between the capacitors

• p.d. is split by half

Answer explanation

During a capacitor is charging, starts with pd=0 and then exponentially grows up to pd=emf of the battery.

What will be the total capacitance?

• Inverse of the individual inverses

• Just add individual capacitances.

• It will be the magnitude of the minimum.

Answer explanation

Capacitors are opposite to resistors.

What will be the total capacitance if we increase C1?

• It will decrease and p.d. on C1 too.

• It will increase and p.d. on C1 too.

• It will increase but p.d. on C1 remains constant. (still connected to battery)

• It will decrease but p.d. on C1 remains constant. (still connected to battery)

What will be the total charge on both plates if we increase C1?

• It will remain constant.

• It will increase but p.d. on C1 remains constant. (still connected to battery)

• It will decrease but p.d. on C1 remains constant. (still connected to battery)

What will be the total energy stored on both plates if we increase C1?

• It will remain constant. (charge can't be destroyed)

• It will increase but p.d. on C1 remains constant. (still connected to battery)

• It will decrease but p.d. on C1 remains constant. (still connected to battery)

Answer explanation

If capacitor is connected to battery:

a) pd on plates remain the same.

b) Energy is proportional to Capacitance

c) charge stored can change. (charge remains constant if it is not connected to battery)

What is the total capacitance?

• 
• 
• 
• 

If we increase C1, what is the total capacitance?

• It will increase.

• It will decrease.

• It will remain the same.

Answer explanation

Increasing C1 will increase the total capacitance.

What is the pd on each plate?

• Same as emf of the battery

• pd will be split according to C on each capacitance

• pd will be always the half disregards of C

If we increase C1, what happens to total charge and total energy stored?

• It will decrease because q and E is inversely proportional to C

• It will increase because q and E is inversely proportional to C

• It will decrease because q and E is directly proportional to C

• It will increase because q and E is directly proportional to C

Answer explanation

Remember. This answer is true if capacitors are still connected to the battery.

When a capacitor is disconnected from battery, it keeps the charge.

If we increase C1, what is its pd?

• It will decrease because C is inversely proportional to pd

• It will increase because C is inversely proportional to pd

• It will decrease because C is directly proportional to pd

• It will increase because C is directly proportional to pd

Answer explanation

Changing the capacitance will affect the pd across IF is connected in series.

If C1 is in parallel, pd will remain constant.