12 physics electrostatics test 01 answer 5x7f
TRANSCRIPT
-
8/17/2019 12 Physics Electrostatics Test 01 Answer 5x7f
1/4
Material downloaded from http://myCBSEguide.com and http://onlineteachers.co.in
Portal for CBSE Notes, Test Papers, Sample Papers, Tips and Tricks
01. = between the charges in vaccuum
force between two charges in medium
FV force
FM =
FV Fm
k ⇒ =
⇒ , .
02. ⇒
⇒ . .
03. = = /
,
.
04.
.
05. =
∴ F qE
am m
= = 1
2 2 = 2
∴ = ⇒2 = 2
21 1 mv = (2 as) = mas ----- 2
2 2KE m=
1 . 2
m x SqE
KE m
KE qES
= ×
=
2 E
1 E
-
8/17/2019 12 Physics Electrostatics Test 01 Answer 5x7f
2/4
Material downloaded from http://myCBSEguide.com and http://onlineteachers.co.in
Portal for CBSE Notes, Test Papers, Sample Papers, Tips and Tricks
06.
(+)
.
.
+ = +. + 91
E
2 2
2 2
2 2
( ) ( 9 ) E = E
(10 )
Substituting in eq. 1
( ) ( 9 )
(10 )
(10 ) = 9x 10 = 3x
1010a = 4x x = 9
4
a from change (+q)
Or
10 a - x = 10a - 2.5a = 7.5a from
= 2.5
K q K q A B
x a x
K q K q
x a x
a x a x
x
+ +⇒ =
−
+ +=
−
− −
⇒
⇒
change (+9q)
07.
.
(2 )P q l=
.. ()
( θ )
( ) E ,
.
τ = ⊥
() =
sin AB sin = 2 sin BN
And BN AB
θ θ θ = ⇒ = ℓ
(τ ) = 2 ℓ θ
(τ ) = θ ( = q(2 ))P l
∵
P E τ = ×
A B
10a
x 10a-x+qv
+q +9qP
B A E
E
-
8/17/2019 12 Physics Electrostatics Test 01 Answer 5x7f
3/4
Material downloaded from http://myCBSEguide.com and http://onlineteachers.co.in
Portal for CBSE Notes, Test Papers, Sample Papers, Tips and Tricks
08. (1) lim
q o→
.
(2) ()
= 2 10 7 + (2 10 7)
= . P
() 2P q l= ×
= 2 107 20 102
= 4 108
.
09. ()
()
2 2
2 2
( )
( )
Kq E q
r aKq
E qr a
Since E q E q
+ =+
− =+
+ = −
∴ Enet
.
(-2x10-7
Z
Z
Y
X
(0,0,10)cm
2l=10+10=20cm
(2x10-7
)
(0,0,-10)cm
P
E+q
2 2r a+
2 2r a+
2
E
(+qo) E= ?
-q
r
A B(-q) (+q)a o a
θ θ
θ P
E
net
-
8/17/2019 12 Physics Electrostatics Test 01 Answer 5x7f
4/4
Material downloaded from http://myCBSEguide.com and http://onlineteachers.co.in
Portal for CBSE Notes, Test Papers, Sample Papers, Tips and Tricks
2 2
-q
2 2
2
2 2 2 2
2 2
2 2
2 2 2 2
2 E cos2
2 2 cos 2
2 (1 cos 2 )
2 2cos 4 cos
2 cos cos =
2
2
2
(
q q q
q q
q
q q
Enet E E E
Enet E E
Enet E
Enet E E
a Enet E
r a
a Enet E
r a
kq a Enet
r a r a
k aq Enet
r
θ
θ
θ
θ θ
θ θ
− +
+
= + + +
= + +
= + +
= + = +
= +
+
= +
+
=+ +
=
2 2 3/2 2 2 3/2
3
For r >>> a (a can be neglected)
Enet =
) ( )
K P
a r a
KP
r
=+ +