SHORT TEST
Roll #
Q.1
PHYSICS
Second year
Name
Ch 12 b
OBJECTIVE
Encircle the best answer. Cutting over-writing is not allowed
Marks:04
4
i. Energy is being stored in _____ between plates of capacitor.
a . Dielectric
b. electric field
c. charges d. Potential energy
ii.
______ equal and opposite charges separated by small distance
forms a dipole:
(a) two
(b) three
(c) four
(d) six
iii.
Potential difference between the plates decreases by _____ E :
(a) Increasing
(b) Decreasing (c) skipping
(d) not effecting
iv.
Larger value of “RC” means _______ discharge of capacitor:
(a) Slow
(b) fast
(c) moderate
SUBJECTIVE
Q.2 Answer the following short questions
(d) no
Marks: 16
02x 04 =08 marks
a) Prove that resistance times Farad equals second.
b) How can you identify that which plate of a capacitor is positively charged?
c) Shortly explain the process of charging of a capacitor.
d) Write down the process of polarization of dielectrics.
Extensive
Q.3 (a) Define capacitance. Derive the relation for capacitance of a capacitor with
and without dielectric. Also define dielectric constant.
1+3+1=5 marks
(b) A capacitor has capacitance of 2.5x10-8F. How many electrons are transferred
from one plate to other when 450 v are applied?
3 marks