Department of Pre-University Education, KarnatakaPUC Karnataka Science Class 12
Advertisement Remove all ads

A 100 Pf Capacitor is Charged to a Potential Difference of 24 V. It is Connected to an Uncharged Capacitor of Capacitance 20 Pf. What Will Be the New Potential Difference Across the 100 Pf Capacitor? - Physics

Sum

A 100 pF capacitor is charged to a potential difference of 24 V. It is connected to an uncharged capacitor of capacitance 20 pF. What will be the new potential difference across the 100 pF capacitor?

Advertisement Remove all ads

Solution

Given : 

`C_1 = 100   "pF"`

V = 24 V

Charge on the capacitor `q = C_1V = 24 xx 100  "pC"`

Capacitance of the uncharged capacitor, `C_2 = 20  "pF"`

When the charged capacitor is connected with the uncharged capacitor, the net charge on the system of the capacitors becomes 

`q_1 + q_2 = 24 xx 100  "qC"`             ....(i)

The potential difference across the plates of the capacitors will be the same.
Thus,

`q_1/C_1 = q_2/C_2`

⇒ `q_1/100 = q_2/20`

⇒ `q_1 = 5q_2`                ....................(ii)

From eqs. (i) and (ii), we get

`q_1+q_1/5 = 24 xx 100  "pc"`

⇒ `6q_1 = 5 xx 24 xx 100  "pC"`

⇒ `q_1 = (5xx24xx100)/(6) "pC"`

Now ,

`V_1 = q_1/C_1`

⇒ `(5xx24xx100  "pC")/(6xx100  "pF")` = 20 V

  Is there an error in this question or solution?
Advertisement Remove all ads

APPEARS IN

HC Verma Class 11, Class 12 Concepts of Physics Vol. 2
Chapter 9 Capacitors
Q 19 | Page 166
Advertisement Remove all ads
Advertisement Remove all ads
Share
Notifications

View all notifications


      Forgot password?
View in app×