phy204
May 13, 2012, 04:56 PM
1 The force per unit charge refers to ---------
electric potential
electric current
elctric field
electromotive force
2 An insulating material is said to be --------
paramagnetic
dieletric
superconducting
semiconducting
3 An electric field has a magnitude of 350N/C and makes an angle of 50o at each point on a flat rectangular horizontal surface of dimensions 20cm by 15cm. Calculate the electric flux for this surface
6 72Nm2 C
1 67Nm2 C
8 23Nm2 C
7 36Nm2 C
4 An electrical device in which two parallel conducting plates are in proximity but separated by an insulating material is called a ---------
inductor
resistor
capacitor
semiconductor
5 Two parallel conducting plates of area 100cm-squared in a vacuum are each given equal but opposite charges of 8 9 10−7C . What is the magnitude of the electric field between the plates? Take o=8 85 10−12C2 Nm2
107N C
206N C
303N C
404N C
6 A 2.0F capacitor is desired. What should be the area of the plates if they are to be separated by a 4.5mm air gap? Take o=8 85 10−12C2 Nm2
107m2
205m2
109m2
303m2
7 Capacitance of a capacitor depends on all of the following EXCEPT -------------
potential difference across the capacitor
area of the plates of the capacitor
distance of one plate from the other
electric current through the capacitor
8 Find the charge on a 1000 pF capacitor when charged to a voltage of 24V
0.24 C
0.048 C
0.024 C
0.48 C
9 Calculate the electric field between two plates which are 2cm apart in a vacuum and connected to a 120v battery
2400V/m
6000V/m
3000V/m
4000V/m
10 A 1.2 microfarad capacitor is charged to 3 kV. Calculate the energy stored in the capacitor
5.4J
3.3J
1.7J
12.8J
11 Two identical capacitors are connected in parallel, charged by a battery of voltage V, and then isolated from the battery. One of the capacitors is then filled with a material of relative permittivity K. What is the final potential difference across the plates of the capcitor
2KV
2V/K
2V/(K+1)
2V/(K-1)
12 Which of the following correctly represents the dimensions of dipole moment?
[charge]
[length]
[carge][length]
[charge]/[length]
13 A neutral molecule placed in an electric field becomes ------------
discharged
ionised
polarised
charged
14 A molecule in which the centre of the electron cloud does NOT coincide with the cenre of the nuleus is called ----------- molecule
dielectric
ferromagnetic
polar
diamagnetic
15 Which of the following statements is correct?
polar molecule has induced dipole moment
a non-polar molecule has permanent dipole moment
a non-polar molecule acquires a dipole moment in the presence of an electric field
a polar molecule acquires permanent dipole moment in the presence of an electric field
16 When a rectangular dielectric slab is placed in an electric field,
polarisation charges appear on the surfaces of the dielectric perpendicular to the field
surface charges appear on the surfaces of the dielectric parallel to the field
the induced dipole moment decreases with increase in the field
surface density of bound charges does not depend on the shape of the dielectric material
17 The correct dimensions of polarisation is ----------
[charge]/[length]
[charge][length]
[charge]/[length squared]
[charge]/[length cubed]
18 A dielectric material in which the magnitude and direction of the induced dipole momement do not depend on the orientation of the crystal axis with respect to the direction of the external electric field is called --------- dielectric
crystalline
amorphous
anisotropic
isotropic
19 A surface element of a dielectric material dS is inclined at an angle A to the direction of the external electric field. Given that the dipole moment per unit volume is P, then surface charge density aqcuired by the material is
PdSsinA
PdStanA
PdScotA
PdScosA
20 A device usually used for storing charges in electrical circuits is ---------------
inductor
capacitor
resistor
insulator
electric potential
electric current
elctric field
electromotive force
2 An insulating material is said to be --------
paramagnetic
dieletric
superconducting
semiconducting
3 An electric field has a magnitude of 350N/C and makes an angle of 50o at each point on a flat rectangular horizontal surface of dimensions 20cm by 15cm. Calculate the electric flux for this surface
6 72Nm2 C
1 67Nm2 C
8 23Nm2 C
7 36Nm2 C
4 An electrical device in which two parallel conducting plates are in proximity but separated by an insulating material is called a ---------
inductor
resistor
capacitor
semiconductor
5 Two parallel conducting plates of area 100cm-squared in a vacuum are each given equal but opposite charges of 8 9 10−7C . What is the magnitude of the electric field between the plates? Take o=8 85 10−12C2 Nm2
107N C
206N C
303N C
404N C
6 A 2.0F capacitor is desired. What should be the area of the plates if they are to be separated by a 4.5mm air gap? Take o=8 85 10−12C2 Nm2
107m2
205m2
109m2
303m2
7 Capacitance of a capacitor depends on all of the following EXCEPT -------------
potential difference across the capacitor
area of the plates of the capacitor
distance of one plate from the other
electric current through the capacitor
8 Find the charge on a 1000 pF capacitor when charged to a voltage of 24V
0.24 C
0.048 C
0.024 C
0.48 C
9 Calculate the electric field between two plates which are 2cm apart in a vacuum and connected to a 120v battery
2400V/m
6000V/m
3000V/m
4000V/m
10 A 1.2 microfarad capacitor is charged to 3 kV. Calculate the energy stored in the capacitor
5.4J
3.3J
1.7J
12.8J
11 Two identical capacitors are connected in parallel, charged by a battery of voltage V, and then isolated from the battery. One of the capacitors is then filled with a material of relative permittivity K. What is the final potential difference across the plates of the capcitor
2KV
2V/K
2V/(K+1)
2V/(K-1)
12 Which of the following correctly represents the dimensions of dipole moment?
[charge]
[length]
[carge][length]
[charge]/[length]
13 A neutral molecule placed in an electric field becomes ------------
discharged
ionised
polarised
charged
14 A molecule in which the centre of the electron cloud does NOT coincide with the cenre of the nuleus is called ----------- molecule
dielectric
ferromagnetic
polar
diamagnetic
15 Which of the following statements is correct?
polar molecule has induced dipole moment
a non-polar molecule has permanent dipole moment
a non-polar molecule acquires a dipole moment in the presence of an electric field
a polar molecule acquires permanent dipole moment in the presence of an electric field
16 When a rectangular dielectric slab is placed in an electric field,
polarisation charges appear on the surfaces of the dielectric perpendicular to the field
surface charges appear on the surfaces of the dielectric parallel to the field
the induced dipole moment decreases with increase in the field
surface density of bound charges does not depend on the shape of the dielectric material
17 The correct dimensions of polarisation is ----------
[charge]/[length]
[charge][length]
[charge]/[length squared]
[charge]/[length cubed]
18 A dielectric material in which the magnitude and direction of the induced dipole momement do not depend on the orientation of the crystal axis with respect to the direction of the external electric field is called --------- dielectric
crystalline
amorphous
anisotropic
isotropic
19 A surface element of a dielectric material dS is inclined at an angle A to the direction of the external electric field. Given that the dipole moment per unit volume is P, then surface charge density aqcuired by the material is
PdSsinA
PdStanA
PdScotA
PdScosA
20 A device usually used for storing charges in electrical circuits is ---------------
inductor
capacitor
resistor
insulator