Download XII Cycle Test I - SBIOA Model Matriculation And Higher Secondary

S.B.I.O.A. MODEL MATRIC AND HIGHER SECONDARY SCHOOL, CHENNAI – 37
CYCLE TEST – I
STD. XII
PHYSICS
TIME : 1 HR.
CODE – A
MAX. MARKS : 50
I. ANSWER THE FOLLOWING:
10 X 3 = 30
1. State Coulomb’s law in electrostatics.
2. What is a dipole? Define dipole moment.
3. Differentiate polar and non polar molecules.
4. What is meant by quantization of charges?
5. Define potential at a point.
6. Give the uses of capacitors.
7. What is corona discharge? Where is it used?
8. What is meant by electrostatic shielding?
9. Three small identical balls have charges -3 x 10-12 C, 8 x10-12 C and 4 x 10-12 C respectively. They
are brought in contact and then separated. Calculate (i) the charge on each ball (ii) no. of electrons
in excess or deficit in each ball after contact.
10. Two charges +q and -3q are separated by a distance of 1m. At what point between the charges on
the axis is the potential zero?
II. ANSWER THE FOLLOWING:
2 X 5 = 10
11. Derive an expression for the energy stored in a capacitor.
12. Two charges 10 x 10-9 C and 20 x 10-9 C are placed at a distance of 0.3 m apart. Find the potential
and intensity at a point midway between them.
OR
A parallel plate capacitor has plates of area 200 cm2 and separation between the plates is 1 mm.
Calculate (i) the potential difference between the plates if a 1 nC charge is given to the capacitor
(ii) with the same charge the separation between the platers is increased to 2 mm, what is the new
potential difference and (iii) the electric field between the plates.
III. ANSWER THE FOLLOWING:
1 X 10 =10
13. Derive an expression for the electric field at a point on the axial line of the dipole.
OR
Explain the principle of a capacitor. Derive an expression for the capacitance of a parallel plate
capacitor.
S.B.I.O.A. MODEL MATRIC AND HIGHER SECONDARY SCHOOL, CHENNAI – 37
CYCLE TEST – I
STD. XII
PHYSICS
TIME : 1 HR.
CODE – B
MAX. MARKS : 50
I. ANSWER THE FOLLOWING:
10 X 3 = 30
1. State Gauss’s law in electrostatics.
2. Define electric flux and give its unit .
3. What is permittivity and relative permittivity? How are they related?
4. What is meant by additive nature of charges?
5. Define potential difference.
6. Give the properties of lines of force.
7. Explain the working of a microwave oven.
8. What is meant by electrostatic induction?
9. Three capacitors 10 µF, 20 µF and 30 µF are connected in parallel with a 100 V battery. What is the
total energy stored in the combination of capacitors?
10. A sample of HCl gas is placed in an electric field of 2.5 x 104 NC-1. The dipole moment of each
molecule is 3.4 x 10-30 C m. Find the maximum torque that can act on a molecule.
II. ANSWER THE FOLLOWING:
2 X 5 = 10
11. Derive an expression for the potential energy of a dipole.
12. Two insulated charged spheres of charges 6.5 x 10-7 C each are separated by a distance of 0.5 m.
Calculate the electrostatic force between them. Also calculate the force (i) when the charges are
doubled and the distance of separation is halved. (ii) when the charges are placed in a dielectric
medium water (εr = 80)
OR
A spherical conductor of radius 0.12 m has a charge of 1.6 x 10-7 C distributed uniformly on its
surface. What is the electric field (i) inside the sphere (ii) on the sphere (iii) at a point 0.18 m
from the centre of the sphere?
III. ANSWER THE FOLLOWING:
1 X 10 =10
13. Derive an expression for the electric field at a point on the equatorial line of the dipole.
OR
What is a capacitor? Derive an expression for the capacitance of a parallel plate
capacitor when a dielectric is introduced.
S.B.I.O.A. MODEL MATRIC AND HIGHER SECONDARY SCHOOL, CHENNAI – 37
CYCLE TEST – I
STD. XII
PHYSICS – OBJECTIVE TEST
TIME : 1 HR.
CODE – A
MAX. MARKS : 50
S.NO.
QUESTION
1.
If a system consists of three charges 3q, 4q and -5q,
then the total charge of the system is _________
a) 2q b) -2q c) 5q d) 12q
2.
The value of permittivity of free space is _________
a) 8.854 x 1012 C2 N-1 m-2 b) 8.854 x 10-12 C2 N-1 m-2
c) 8.854 x 1012 C2 N1 m2 d) 8.854 x 10-12 C2 N1 m2
3.
If the distance between two charges is doubled, then
the force between the charges will be _________
a) four times more b) four times less
c) two times more d) two times less
4.
5.
If a proton is moved against the coulomb force of an
electric field ________
a) work is done by the field
b) energy is used from some outside source
c) the strength of the field is decreased
d) the energy of the system is decreased
In vacuum the force between two charges is _______
a) F =
b) F =
c) F =
6.
7.
8.
9.
The unit for k =
d) F =
is ________
a) NmC-1 b) Nm2C-1 c) Nm-2C-1 d) Nm2C
The relative permittivity of a medium is also known
as _______
a) permeability
b) permittivity
c) dielectric constant
d) relative permeability
Inverse square law helps us to define _________
a) force b) charge c) newton d) coulomb
If a charge of q coulomb placed at a point
experiences a force of F newton, then the electric
OPTION
ANSWER
field intensity is _________
a) E =
b) E =
c) E =
10.
11.
12.
13.
14.
d) E =
The unit of relative permittivity is _________
a) NmC-1 b) Nm2C-1 c) Nm-2C-1 d) no unit
The force between two charges depends on ________
a) density of the medium
b) permeability of the medium c) nature of the
medium d) size of the medium
The direction dipole moment is _______
a) from +q to –q
b) from –q to +q
c) either a or b
d) none of the above
A unit positive charge gives rise to ______ lines of
force in free space.
a) 1/ εr
b) εr
c) 1/ ε0
d) ε0
The relation between electric field and electric
potential is ________
a)
b)
c)
d)
15.
The potential at a point on the equatorial line of an
electric dipole is _________
a) infinity b) zero c)
d)
16.
The torque acting on an electric dipole in an uniform
electric field is _________
a) pE cosθ b) pE sin θ c) –pE sin θ d) 0
Electric potential energy is measured in terms of
_________
a) force b) work done c) intensity d) electric field
The unit of electric flux is ________
a) NmC-1 b) Nm2C-1 c) Nm-2C-1 d) no unit
The electric field due to an infinite plane sheet of
charge is ________
a) independent of the charge on the sheet
b) independent of the area of the sheet
c) independent of the medium
d) independent of the distance of the point from the
sheet
The distribution of charge on a conductor depends on
________
a) only on the shape of the conductor
b) nature of the conductor
c) only on the proximity of the conductors
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
32.
32.
d) on the shape and proximity of the conductors
Lightning arrestors work on the principle of _______
a) induction b) action of points c) conduction
d) electromagnetic induction
Van de Graff generators are used to obtain potential
of the order of _______ V.
a) 10-6 b) 106 c) 107 d) 10-7
The capacitance of a condenser is given by _______
a) C = q/V b) C = qV c) V = C/q d) V = qC
If a dielectric is introduced in a parallel plate
capacitor, it tends to ________
a) increase the capacitance b) decrease the
capacitance c) neither increase nor decrease d) first
increases and then decreases
The commonly used dielectric is _______
a) air b) oil c) water d) wood
Two point chargesd +4q and +q are placed 30 cm
apart. At what point on the line joining them is the
electric field zero?
a) 15 cm from +q
b) 7.5 cm from +q
c) 20 cm from +4q
d) 5 cm from +q
The electrostatic force between two charges kept at a
distance d apart in a medium εr = 6 is 0.3 N. The
force between them at the same separation is ______
a) 20 N b) 0.5 N c) 1.8 N d) 2 N
Electric field intensity is 400 V/m at a distance of 2 m
from a point charge. It will be 100 V/m at a distance
of _______
a) 50 cm b) 4 cm c) 4 m d) 1.5 m
A dipole is placed with its axis parallel to a uniform
electric field. It experiences ________
a) only a net force b) both a net force and a torque
c) only torque
d) neither a net force nor torque
A dipole is placed at angle θ in an uniform electric
field. It experiences ________
a) only a net force b) both a net force and a torque
c) only torque
d) neither a net force nor torque
A dipole is placed in a non-uniform electric field. It
experiences ________
a) only a net force b) both a net force and a torque
c) only torque
d) neither a net force nor torque
If a point lies at a distance x from the midpoint of a
dipole, the electric potential at this point is _______
a) directly proportional to x2
b) inversely proportional to x2
c) directly proportional to 1/x2
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
d) none of the above
Electric potential energy of two point charges is
_______
a)
b)
c) pE cosθ
d) pE sinθ
Electric potential energy of a dipole in an electric
field is _______
a)
b)
c) pE cosθ
d) pE sinθ
The work done in moving a 500µC charge between
two points on an equipotential surface is _______
a) zero b) finite positive c) finite negative d) infinity
The work done in moving a 500µC charge between
two points whose potential difference is 5 V is
_______
a) zero b) finite positive c) finite negative d) infinity
Which of the following quantities is a scalar?
a) dipole moment
b) electric field
c) electric potential d) electric force
The number of lines of force originating from a
charge of 1C is _________
a) 1.129 b) 1.129 x 1011 c) 1.129 x10-11
d) 1.6 x 1018
The number of lines of force originating from a
charge of 1µC is _________
a) 1.129 x 105 b) 1.129 x 1011 c) 1.129 x10-11
d) 1.6 x 1018
The electric field outside the plates of two oppositely
charged plane sheets of charge density σ is _______
a) σ/2 ε0 b) -σ/2 ε0
c) σ / ε0 d) zero
The electric field in between the plates of two
oppositely charged plane sheets of charge density σ is
_______
a) σ/2 ε0 b) -σ/2 ε0
c) σ / ε0 d) zero
The electric field in between the plates of two
similarly charged plane sheets of charge density σ is
_______
a) σ/2 ε0 b) -σ/2 ε0
c) σ / ε0 d) zero
A hollow metal ball carrying an electric charge
produces no electric field at points ________
a) outside the sphere b) inside the sphere c) on its
surface d) at a distance more than twice the radius
44.
45.
46.
47.
48.
49.
50.
The capacitance of a parallel plate capacitor increases
from 5µF to 12 µF when a dielectric is filled between
the plates. The dielectric constant of the dielectric is
________
a) 65 b) 55 c) 12 d) 10
When capacitors are connected in parallel, the
_______
a) p.d. across each capacitor is the same
b) charge through each capacitor is the same
c) both a and b
d) neither a nor b
If the p.d between two points 3 cm apart in an electric
field is 30 V, then the electric field intensity between
the points will be _______
a) 20 V/m b) 40 V/m c) 10 V/m
d) 10 V/cm
The force experienced by an electron in an electric
field of intensity 103 V/m is ________
a) 1.6 x 10-19 N
b) 1.6 x 10-16 N
19
c) 1.6 x 10 N
d) 1.6 x 10-10 N
Distribution of charges on a conductor depends on
_______
a) size b) shape c) mass d) area
Relation between electric field intensity and electric
potential is _______
a) dV = -E dx
b) dE = -V dx
c) dV = -dE
d) dV = dE
The value for εr for air is _______
a) 1 b) 0 c) < 1 d) >1
S.B.I.O.A. MODEL MATRIC AND HIGHER SECONDARY SCHOOL, CHENNAI – 37
CYCLE TEST – I
STD. XII
PHYSICS – OBJECTIVE TEST
TIME : 1 HR.
CODE – B
MAX. MARKS : 50
S.NO.
QUESTION
1.
Two point chargesd +4q and +q are placed 30 cm
apart. At what point on the line joining them is the
OPTION
ANSWER
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
electric field zero?
a) 15 cm from +q
b) 7.5 cm from +q
c) 20 cm from +4q
d) 5 cm from +q
The electrostatic force between two charges kept at a
distance d apart in a medium εr = 6 is 0.3 N. The
force between them at the same separation is ______
a) 20 N b) 0.5 N c) 1.8 N d) 2 N
Electric field intensity is 400 V/m at a distance of 2 m
from a point charge. It will be 100 V/m at a distance
of _______
a) 50 cm b) 4 cm c) 4 m d) 1.5 m
A dipole is placed with its axis parallel to a uniform
electric field. It experiences ________
a) only a net force b) both a net force and a torque
c) only torque
d) neither a net force nor torque
A dipole is placed at angle θ in an uniform electric
field. It experiences ________
a) only a net force b) both a net force and a torque
c) only torque
d) neither a net force nor torque
A dipole is placed in a non-uniform electric field. It
experiences ________
a) only a net force b) both a net force and a torque
c) only torque
d) neither a net force nor torque
If a point lies at a distance x from the midpoint of a
dipole, the electric potential at this point is _______
a) directly proportional to x2
b) inversely proportional to x2
c) directly proportional to 1/x2
d) none of the above
Electric potential energy of two point charges is
_______
a)
b)
c) pE cosθ
d) pE sinθ
Electric potential energy of a dipole in an electric
field is _______
a)
b)
c) pE cosθ
d) pE sinθ
The work done in moving a 500µC charge between
two points on an equipotential surface is _______
a) zero b) finite positive c) finite negative d) infinity
The work done in moving a 500µC charge between
two points whose potential difference is 5 V is
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
_______
a) zero b) finite positive c) finite negative d) infinity
Which of the following quantities is a scalar?
a) dipole moment
b) electric field
c) electric potential d) electric force
The number of lines of force originating from a
charge of 1C is _________
a) 1.129 b) 1.129 x 1011 c) 1.129 x10-11
d) 1.6 x 1018
The number of lines of force originating from a
charge of 1µC is _________
a) 1.129 x 105 b) 1.129 x 1011 c) 1.129 x10-11
d) 1.6 x 1018
The electric field outside the plates of two oppositely
charged plane sheets of charge density σ is _______
a) σ/2 ε0 b) -σ/2 ε0
c) σ / ε0 d) zero
The electric field in between the plates of two
oppositely charged plane sheets of charge density σ is
_______
a) σ/2 ε0 b) -σ/2 ε0
c) σ / ε0 d) zero
The electric field in between the plates of two
similarly charged plane sheets of charge density σ is
_______
a) σ/2 ε0 b) -σ/2 ε0
c) σ / ε0 d) zero
A hollow metal ball carrying an electric charge
produces no electric field at points ________
a) outside the sphere b) inside the sphere c) on its
surface d) at a distance more than twice the radius
The capacitance of a parallel plate capacitor increases
from 5µF to 12 µF when a dielectric is filled between
the plates. The dielectric constant of the dielectric is
________
a) 65 b) 55 c) 12 d) 10
If a system consists of three charges 3q, 4q and -5q,
then the total charge of the system is _________
a) 2q b) -2q c) 5q d) 12q
The value of permittivity of free space is _________
a) 8.854 x 1012 C2 N-1 m-2 b) 8.854 x 10-12 C2 N-1 m-2
c) 8.854 x 1012 C2 N1 m2 d) 8.854 x 10-12 C2 N1 m2
If the distance between two charges is doubled, then
the force between the charges will be _________
a) four times more b) four times less
c) two times more d) two times less
If a proton is moved against the coulomb force of an
electric field ________
a) work is done by the field
24.
b) energy is used from some outside source
c) the strength of the field is decreased
d) the energy of the system is decreased
In vacuum the force between two charges is _______
a) F =
b) F =
c) F =
25.
26.
27.
28.
29.
30.
32.
32.
33.
34.
The unit for k =
d) F =
is ________
a) NmC-1 b) Nm2C-1 c) Nm-2C-1 d) Nm2C
The relative permittivity of a medium is also known
as _______
a) permeability
b) permittivity
c) dielectric constant
d) relative permeability
Inverse square law helps us to define _________
a) force b) charge c) newton d) coulomb
If a charge of q coulomb placed at a point
experiences a force of F newton, then the electric
field intensity is _________
a) E =
b) E =
c) E =
d) E =
The unit of relative permittivity is _________
a) NmC-1 b) Nm2C-1 c) Nm-2C-1 d) no unit
The force between two charges depends on ________
a) density of the medium
b) permeability of the medium
c) nature of the medium d) size of the medium
The force experienced by an electron in an electric
field of intensity 103 V/m is ________
a) 1.6 x 10-19 N
b) 1.6 x 10-16 N
19
c) 1.6 x 10 N
d) 1.6 x 10-10 N
Distribution of charges on a conductor depends on
_______
a) size b) shape c) mass d) area
Relation between electric field intensity and electric
potential is _______
a) dV = -E dx
b) dE = -V dx
c) dV = -dE
d) dV = dE
The value for εr for air is _______
a) 1 b) 0 c) < 1 d) >1
35.
36.
37.
The direction dipole moment is _______
a) from +q to –q
b) from –q to +q
c) either a or b
d) none of the above
A unit positive charge gives rise to ______ lines of
force in free space.
a) 1/ εr
b) εr
c) 1/ ε0
d) ε0
The relation between electric field and electric
potential is ________
a)
b)
c)
d)
38.
The potential at a point on the equatorial line of an
electric dipole is _________
a) infinity b) zero c)
d)
39.
The torque acting on an electric dipole in an uniform
electric field is _________
a) pE cosθ b) pE sin θ c) –pE sin θ d) 0
Electric potential energy is measured in terms of
_________
a) force b) work done c) intensity d) electric field
The unit of electric flux is ________
a) NmC-1 b) Nm2C-1 c) Nm-2C-1 d) no unit
The electric field due to an infinite plane sheet of
charge is ________
a) independent of the charge on the sheet
b) independent of the area of the sheet
c) independent of the medium
d) independent of the distance of the point from the
sheet
The distribution of charge on a conductor depends on
________
a) only on the shape of the conductor
b) nature of the conductor
c) only on the proximity of the conductors
d) on the shape and proximity of the conductors
Lightning arrestors work on the principle of _______
a) induction b) action of points c) conduction
d) electromagnetic induction
Van de Graff generators are used to obtain potential
of the order of _______ V.
a) 10-6 b) 106 c) 107 d) 10-7
The capacitance of a condenser is given by _______
a) C = q/V b) C = qV c) V = C/q d) V = qC
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
If a dielectric is introduced in a parallel plate
capacitor, it tends to ________
a) increase the capacitance b) decrease the
capacitance c) neither increase nor decrease d) first
increases and then decreases
The commonly used dielectric is _______
a) air b) oil c) water d) wood
When capacitors are connected in parallel, the
_______
a) p.d. across each capacitor is the same
b) charge through each capacitor is the same
c) both a and b
d) neither a nor b
If the p.d between two points 3 cm apart in an electric
field is 30 V, then the electric field intensity between
the points will be _______
a) 20 V/m b) 40 V/m c) 10 V/m
d) 10 V/cm