Q.1
Force of attraction between the plates of a parallel plate capacitor is
  • a)
    ch-13_qn-193choice_img_no1.png
  • b)
    ch-13_qn-193choice_img_no2.png
  • c)
    ch-13_qn-193choice_img_no3.png
  • d)
    ch-13_qn-193choice_img_no4.png
Q.2
six equal capacitors each of capacitance C are connected as shown in figure. Then equivalent capacitance between A and B is
ch-13_que_no-194_img_no1.png
  • a) 6C
  • b) C
  • c)2C
  • d)C/2
Q.3
A capacitor is charged by using a battery, which is then disconnected. A dielectric slab is then slipped between the plates which results in [ MPPMT 1995]
  • a) reduction of charge on the plates and increase of potential difference across the plates
  • b) increase in the potential difference across the plates, reduction in stored energy, but no change in the charge on the plates
  • c)decrease in the potential difference across the plates, reduction in the stored energy, but no change in the charge on the plates
  • d)none of the above
Q.4
the combined capacit of the parallel combination of two capacitor is four times their combined capacity when connected in series. This means that [ EAMCET 1994]
  • a)their capacites are equal
  • b) their capacities are 1µF and 2µF
  • c)their capacities are 0.5µF and 2µF
  • d)their capacities are infinite
Q.5
Figure a shows two capacitors connected in series and joined to a battery. The graph in figure (b) shows the variation in potential as one moves from left to right on the branch containing the capacitors if. [ MPPMT 1999]
ch-13_que_no-198_img_no1.png
  • a) C1 > C2
  • b) C1=C2
  • c)C1 < C2
  • d)the information is not sufficient to decide the relation between C1 and C2
Q.6
The capacity of a parallel plate condenser depends on [ MPPMT 1994]
  • a) the type of metal used
  • b) the thickness of plates
  • c)the potential applied across the plates
  • d)the separation between the plates
Q.7
The force between the plates of parallel plate capacitor of capacitance C and distance of separation of plate d with potential difference V between the plates, is [ MPPMT 1999]
  • a) CV2 / 2d
  • b) C2V2 / 2d2
  • c) C2V2 / d2
  • d)V2d / C
Q.8
The numerical value of the charge on either plate of the capacitor C shown in the figure is
ch-13_que_no-201_img_no1.png
  • a)CE
  • b) CER1 / (R2 + r )
  • c)CER2 / (R2 + r )
  • d) CER1 / (R1 + r )
Q.9
Separation between the plates of a parallel plate capacitor is d and the area of each plate is A. When a slab of material of dielectric constant K and thickness t is introduced between the plates, its capacitance becomes [ MPPMT 1989]
  • a)
    ch-13_qn-202choice_img_no1.png
  • b)
    ch-13_qn-202choice_img_no2.png
  • c)
    ch-13_qn-202choice_img_no3.png
  • d)
    ch-13_qn-202choice_img_no4.png
Q.10
Two metal spheres of capacitance C1 and C2 carry some charges. They are put in contact and then separated. the final charges Q1 and Q2 on then will satisfy [ MPPMT 1999]
  • a)
    ch-13_qn-203choice_img_no1.png
  • b)
    ch-13_qn-203choice_img_no2.png
  • c)
    ch-13_qn-203choice_img_no3.png
  • d)
    ch-13_qn-203choice_img_no4.png
Q.11
Each capacitor in figure has capcity 5µF. The voltmeter, connected in parallel reads 100V. The charge on each plate of cpacirtor is
ch-13_que_no-204_img_no1.png
  • a) 0.05 mC
  • b) 0.5 mC
  • c) 5 mC
  • d) 1 mC
Q.12
The capacity of paralel plate ccondenser is 10µF without dielectric. Dielectric of constant 2 is used to fill half the thickness between the plates the capacitance in µF is .. [ EAMCET 1995]
  • a)10
  • b) 20
  • c)15
  • d)13.33
Q.13
An electron moving along the positive x-axis with speed of 3×106 m/s enters the region of a uniform electric field. The electron stops after travelling a distance of 90 mm in the field. The electric field strength is [ mass of electron 9.1×10-31 kg]
  • a) 2.84 kV/m, along -ve x-axis
  • b) 0.284 kV/m, along -ve x-axis
  • c)0.284 kV/m, along +ve x-axis
  • d)28.4 kV/m, along +ve x-axis
Q.14
An electric dipole of moment p is placed normal to the line of force of electric field E, then work done in defleting it through an angle of 180 degree is
  • a) pE
  • b) +2pE
  • c) -2PE
  • d) zero
Q.15
SI unit of electric permitivity is
  • a) N m2C-2
  • b) Am-1
  • c) N/C
  • d) C2/ N m2
Q.16
A finite ladder is constructed by connecting several sections of 2µF, 4µF capacitor combinations as shown in figure. It is terminated by a capacitor C. What value should be chosen for C, such that the equivalent capacitance of the ladder between the points A and B becomes independent of the number of sections in between? [ MPPMT 1999]
ch-13_que_no-206_img_no1.png
  • a) 4 µF
  • b) 2 µF
  • c)18µF
  • d)6 µF
Q.17
The value of one Farad in e.s.u. will be [ PET 1998]
  • a) 3×1010
  • b)9×1010
  • c)(1/9)×10-11
  • d)(1/3)×1010
Q.18
Capacitance of a capacitor made by a thin metal foil is 2µF. If the foil is folded with paper of thickness 0.15 mm, and dielectric constant of paper is 2.5, width of paper is 40 mm, then length o foil will be [ Raj. PET 1997]
  • a) 0.34 m
  • b) 1.33 m
  • c) 13.4 m
  • d) 339 m
Q.19
Condenser A has a capacity of 15µF when it is filled with a medium of dielectric constantAnother condener B has a capacity 1µF with air between the plates. Both are charged separately by battery of 100V. After charging, both are connected in parallel with the and dielectric material being removed. The common potential now is [ MNR 1994]
  • a)400 V
  • b) 800 V
  • c)1200 V
  • d)1600 V
Q.20
Between the plates of parallel plate condenser there is 1mm thick paper of delectric constant . It it is charged at 100 V. the eletric field in Volt/metre between the plates of the capacitor is... [ MPPMT 1994]
  • a) 100
  • b) 100000
  • c)25000
  • d)400000
Q.21
Find the resultant capacitance between A and B [ Raj. PET 1997]
ch-13_que_no-211_img_no1.png
  • a)(2/3)µF
  • b) (8/3)µF
  • c)(6/5)µF
  • d)(7/3)µF
Q.22
The area of plates of parallel plate condenser is A and the distance between the plate is 10 mm. There are two dielectric sheets in it, one of dielectricconstant 10 and thick ness 6 mm and other of dielectric constant 5 and thickness 4mm. The capacity of the condenser is [ MPPMT 1997]
  • a) (12/35) εoA
  • b) (2/3) εoA
  • c) (5000/7) εoA
  • d) (12/35) εoA
Q.23
A condenser of capacity C1 is charged to a potential Vo. The eletrcostatic energy stored in it is Uo. It is connected to another uncharged condenser of capacity C2 in parallel. The energy dissipated in the process is [ MPPMT 1994]
  • a)C2Uo) / (C1 + C2)
    ch-13_qn-213choice_img_no3.png
  • b) C1Uo) / (C1 + C2)
    ch-13_qn-213choice_img_no4.png
  • c)
  • d)
Q.24
An air capacitor of capacity C=10µF is connected to a constant voltage battery of 12V. Now, the space is filled with a liquid of dielectric constantThe charge that flow now from battery to the capacitor is [ MPPMT 1997]
  • a) 120 µC
  • b) 600 µC
  • c)480 µC
  • d)24 µC
Q.25
An automobile spring extends 0.2m from 5000N load. The ratio of potential energy stored in this spring when it has been compressed by 0.2m to the potential energy stored in 10µF capacitor at a potential difference of 10,000V is [ B>HU 1996]
  • a)2
  • b)1/2
  • c)1
  • d)1/4
Q.26
A parallel plate capacitor C is connected to a battery and is charged to a potential difference V. Another capacitor of capacitance 2C is connected to another battery and is charged to potential difference 2V. The charging batteries are now disconnected and the capacitors are connected in parallel to each other in such a way that the positive terminal of one is connected to the negative terminal of the other. The final energy of the configuration is [ IIT 1995]
  • a) zero
  • b) 25CV2 / 6
  • c) 3CV2 / 2
  • d) 9CV2 / 2
Q.27
Two point charges placed at a cetrain distance r in air exerts a force of F on each other. Then the distance r' at which these charges will experience the same force in a medium of dlelectric constant K is
  • a)r
  • b) r/K
  • c)r/√K
  • d)r√K
Q.28
An oil drop carrying a charge of 4 electrons has mass of 3.2×10-17 kg. It is falling freely in air with terminal speed. The electric field required to make the drop move upwards with the same speed is ( g=10 ms-2)
  • a) 2×103 V/m
  • b) 1×103 V/m
  • c)3×103 V/m
  • d)8×103 V/m
Q.29
Charges +q, -4q and +2q are arranged at the corners of an equilaterial triangle of side 0.15m. If q=1µC, their mutual potential energy is
  • a) 0.4 J
  • b) 0.5 J
  • c)0.6 J
  • d)0.8 J
Q.30
Due to a charge inside a cube the electric field is Ex=600x1/2 , Ey=Ez=The charge inside the cube is
ch-13_que_no-220_img_no1.png
  • a) 600µC
  • b) 60µC
  • c) 7µµC
  • d) 6µµC
Q.31
Abullet of mass 2g is moving with a speed of 10 m/s. If the bullet has a charge of 2µC, through what potential must it be accelerated, starting from rest to acquire the same speed?
  • a)5 kV
  • b) 5 V
  • c)50 V
  • d)50 kV
Q.32
A hollow sphere of copper is having a uniform charge density of 0.5µC/mIts radius is 0.1 m. ThE potential at the centre of the sphere is
  • a) zero
  • b) 1800π volts
  • c)180π volts
  • d)4.5 kV
Q.33
The force between two short electric dipoles separated by a distance r varies as
  • a) r2
  • b) r4
  • c)r-2
  • d)r-4
Q.34
Two thin concentric hollow conducting spheres of radii R1 and R2 bears changes Q1 and Q2 respectively. If R1 > R2 then the potentil at point distance r such that : ( R1 > r > R2)
  • a)
    ch-13_qn-229choice_img_no1.png
  • b)
    ch-13_qn-229choice_img_no2.png
  • c)
    ch-13_qn-229choice_img_no3.png
  • d)
    ch-13_qn-229choice_img_no4.png
Q.35
Two small spheres carry charge of +3 nC and -12 nC respectively. The charges are distance d apart. The force they exert on one another is FThe spheres are made to touch one another and then separated to distance d apart. The force they exerts on one another is now F2 . Then F1 /F2
  • a) 1
  • b) 2
  • c)1/2
  • d)16:9
Q.36
A cylinder of radius R and length L, is placed in the region of uniform electric field E as shown in figure. The electric flux linked with cylinder is
ch-13_que_no-231_img_no1.png
  • a) R/L
  • b) R2/L
  • c)zero
  • d)infinity
Q.37
Equal and opposite sharges q are placed at point A and B as shown in figure P1 and P2 are equidistant from O. The ratio of P1 . P2 is
ch-13_que_no-232_img_no1.png
  • a) 1
  • b) b/a
  • c) zero
  • d) infinity
Q.38
A is a spherical conductor placed concentrically inside a hollow spherical conductor B, +Q charge is given to A and B is earthed. The electric field intensity is not zero
ch-13_que_no-233_img_no1.png
  • a)inside A
  • b) otside B
  • c)on the surcae of B
  • d)between A and B
Q.39
An insulated sphere of radius R has a uniform charge density λ. The electric field at point P inside the sphere and at distance r from the centre is
ch-13_que_no-234_img_no1.png
  • a) zero
  • b) Rλ / 3εo
  • c)rλ / 3εo
  • d)(2/3) (rλ / εo)
Q.40
A ball of mass 600mg and having charge 5 µC is suspended by a thread in between two parallel plates as shown in figure. The distance between the two plates is 10cm and the potential difference between them is 30V. The tention in the string is
ch-13_que_no-235_img_no1.png
  • a)0.667 m
  • b) 0.5 m
  • c)0.4 m
  • d)0.6 m
Q.41
The work done in carrying a charge of 5µC from point A and B is 8mJ. The difference of potential between A and B is
  • a) 160 V
  • b) 16 V
  • c) 1.6kV
  • d) 16 kV
Q.42
the uncharged matallic sphere A suspended as shown in figure is given a push so that it moves towards +ve plate. Which one of the following statement is correct?
ch-13_que_no-237_img_no1.png
  • a)A touches +ve plate and remain in contact with it
  • b) A touches +ve plate and then moves towards -ve plate and remains in contact with it
  • c)A moves to and fro between the two plates with a constant time period
  • d)A moves to and fro between the two plates with an increasing time-period
Q.43
the number of electric lines of force crossing the surface of an arbitrary curve of surface area S and enclosing a charge q is
  • a) εo
  • b)qεoS
  • c)q/εo
  • d)qV/εo
Q.44
A particle of mass 2gm and charge 1µC is held at rest on a frictionless horizontal surface at a distance of 1 m from the fixed charge of 1 mC. If the particle is released it will be repelled. the speed of the particle when it is at a distance of 10 m from the fixed charge is
  • a) 100 m/s
  • b) 90 m/s
  • c)60 m/s
  • d)45 m/s
Q.45
Charges of 2µC and -3µC are placed at two point A and B distance 1 m as shown in figure. The distance of the point from A, where net potential is zero, is
ch-13_que_no-240_img_no1.png
  • a) 0.667 m
  • b) 0.5 m
  • c) 0.4 m
  • d) 0.6 m
Q.46
In a certain region of space there exists a uniform electric field of 2×103 k V/m. A rectangular coil of dimensions 10cm ×20cm is placed in XY plane. The electric flux through the coil is
  • a)zero
  • b) 4×105
  • c)40
  • d)4
Q.47
Electric potential V at some point in space is zero. This means
  • a) electric field at that point is necessarily zero
  • b) electric field at that point is necessarily non-zero
  • c)electric field at that point may or may not be non-zero
  • d)none of above
Q.48
A charged conductor B is kept inside another hollow uncharged conductor A. B is in contact with A. What will be the effect of charge on B
  • a) Total charge on B is transferred to A and comes on the outer surface of A
  • b) Total charge on B is transferred to A and remains on inner surface of A
  • c)Opposite charge is induced on the outer surface of A
  • d)Charge on B is not transferred to A at all.
Q.49
Charges are placed at the corners of a square of side a as shown in figure. The charge A is in equilibrium. The ratio q1 / q2
ch-13_que_no-244_img_no1.png
  • a) 1
  • b) √2
  • c) 1/√2
  • d) 2√2
Q.50
Mechanical force per unit area of a charged conductor having surface charge density σ is proportional to
  • a)1 / σ2
  • b) σ2
  • c)σ
  • d)√σ
0 h : 0 m : 1 s