MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
Menu
Shane Macguire Grade: upto college level
        A parallel-plate capacitor having plate area 20 cm^2 and separation between the plates 1.00 mm is connected to a battery of 12.0 V. The plates are pulled apart to increase the separation to 2.0 mm. (a) Calculate the charge flown through the circuit during the process. (b) How much energy is absorbed by the battery during the process? (c) Calculate the stored energy in the electric field before and after the process. (d) Using the expression for the force between the plates, find the work done by the person pulling the plates apart. € Show and justify that no heat is produced during this transfer of charge as the separation is increased.
3 years ago

Answers : (1)

Kevin Nash
askIITians Faculty
332 Points
										Sol. area = a = 20 cm^2 = 2 × 10^–2 m^2

d = separation = 1 mm = 10^–3 m
Ci = ε base 0 *2 * 10^-3/10^-3 = 2ε base 0 Cf = ε base 0 * 2 * 10^-3/2 * 10^-3 = ε base 0
q base I = 24 ε base 0 qf = 12 ε base 0 So, q flown out 12 ε base 0. Ie, q base I – q base f.
(a) So, q = 12 × 8.85 × 10^–12 = 106.2 × 10^–12 C = 1.06 × 10^–10 C
(b) Energy absorbed by battery during the process
= q × v = 1.06 × 10^–10 C × 12 = 12.7 × 10^–10 J
(c) Before the process
E base i = (1/2) × Ci × v^2 = (1/2) × 2 × 8.85 × 10^–12 × 144 = 12.7 × 10^–10 J
After the force
E base i = (1/2) × Cf × v^2 = (1/2) × 8.85 × 10^–12 × 144 = 6.35 × 10^–10 J
(d) Workdone = Force × Distance
= 1/2 q^2/ε base 0A = 1 * 10^3 = 1/2*12 * 12 * ε base 0 * ε base 0 * 10^-3/ε base 0 * 2 * 10^-3
(e) From (c) and (d) we have calculated, the energy loss by the separation of plates is equal to the work done by the man on plate. Hence no heat is produced in transformer.
3 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies
  • Complete JEE Main/Advanced Course and Test Series
  • OFFERED PRICE: Rs. 15,000
  • View Details
  • Electricity and Magnetism
  • OFFERED PRICE: Rs. 1,600
  • View Details

Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!! Click Here for details