capacitor

Question 1

capacitor

Answer 1

device that stores electrical energy by separating charge

Question 2

functions of capacitor

Answer 2

• storage of energy
• blocking direct current
• producing direct current
• producing electrical oscillations
• smoothing circuit
• time delay circuit

Question 3

charging capacitor

Answer 3

charged

• capacitor charged up
• electrons moved from top to bottom plate until pd across capacitor = to emf , V supply
• charging process ceases
• current decreases exponentially
• top charged + bottom charged -

Question 4

discharging capacitor

Answer 4

discharged

• discharged through resistor
• current decreases exponentially
• electrons move from bottom to top plate ( reverse )

Question 5

charging and discharging current

similarity
diff

Answer 5

similarity

• charging and discharging pattern same , if same resistor
• graph pg 1

diff
- current flows at opposite direction

Question 6

capacitance

define

Answer 6

charged stored per unit of potential difference across capacitor

formula pg 2
unit - farad

Question 7

why capacitor store energy not charged

Answer 7

• capacitor has equal unit of positive and negative charged
• total charge on capacitor is zero so does not store charge
• positive and negative charges separated
• work done to achieve this so stores energy

Question 8

capacitor can charge up only by

Answer 8

DC current

not AC current cause given one half of cycle is removed the next half

Question 9

product of ohm and farad

Answer 9

s

Question 10

charge stored

Answer 10

capacitance times potential diff across capacitor
Q = CV

not Q = It cause current decreases exponentially not constant