Q.1
A non conducting ring of radius 0.5 m carries a total charge of 1.1×10⁻¹⁰C distributed non-uniformly on its circumference producing an electric field E everywhere in space. The value of the integral ( l=0 being center of ring) in volts is [ IIT 1997]
ch-13_que_no-154_img_no1.png
  • a) +2
  • b) -1
  • c)-2
  • d)zero
Q.2
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.3
A hollow metallic sphere of radius 10cm is given a charge of 3.2×10⁻⁹ C. The electric intensity at a point 4cm from the centre is
  • b) 288 V
  • c)2.88 V
  • d)zero
  • a) 9×10⁻⁹ V
Q.4
How many electrons must be added to spherical conductor of radius 10cm to produce a field of 2×10⁻³ N/C just above the surface
  • a) 1.39×104
  • b) 1.6×105
  • c)3×104
  • d)9.1×104
Q.5
A ball of mass 100 gm and having a charge 4.9×10⁻⁵C is released from rest in vertical region where a horizontal electric field 2×104 N/C exists. The resultant force acting on the ball is
  • a) 1.4 N in the direction of g
  • b) 1.4 N making an angle of 45° with the horizontal
  • c) 0.98 N in the direction of electric field
  • d) 1.96 N along vertical
Q.6
A positively charge oil droplet remains stationary in the electric field between two horizontal plates separated by a distance of 1cm. If the charge on the drop is 9.6×10⁻¹⁶ C and the mass of the droplet is 10-11g. The potential difference between the plates is
  • a)2.0 V
  • b) 3.1 V
  • c)1.02 V
  • d)10.2V
Q.7
The charge on the drop of water is 3×10⁻⁸C. If its surface potential is 500V, its radius must be equal to
  • a)81 cm
  • b) 54 cm
  • c)27 cm
  • d)108cm
Q.8
An electric dipole consists of two opposite charge each of magnitude 1×10⁻⁶ C separated by a distance 2cm. The dipole is placed in electric field of 10×105 N/C. The maximum torque on the dipole is
  • a) 0.2× 10⁻³ N-m
  • b) 1.0×10⁻³ N-m
  • c)2×10⁻³ N-m
  • d)4×10⁻³ N-m
Q.9
A pendulum bob of mass 80mg and carrying a charge of 2×10⁻⁸ C is at rest in a horizontal uniform electric field of 20,000 N/m. Find the tension in the thread of pendulum
  • a) 8.8 × 10⁻² N
  • b) 8.8 × 10⁻³ N
  • c) 8.8 × 10⁻⁴ N
  • d) 8.8 × 10⁻⁵ N
Q.10
An electron is situated 3×10⁻⁹ m from one α-particle and 4×10⁻⁹m from another α particle. The magnitude of force on electron, when two α particles are 5 ×10⁻⁹ m apart is
  • a)5.64×10⁻¹¹ N
  • b) 56.4×10⁻¹¹ N
  • c)0.564×10⁻¹¹N
  • d)564×10⁻¹¹ N
Q.11
Two metal pieces having a potential difference of 800V are 0.02 m apart horizontally. A particle of mass 1.96×10⁻¹⁵ kg is suspended in equilibrium between the plates. If e is elementary charge, then charge on the particle is
  • a) e
  • b) 3e
  • c) 6e
  • d) 8e
Q.12
A non-conducting ring of radius 0.5m carries a total charge of 1.11×10⁻¹C distributed non-uniform;y on its circumference producing electric field everywhere in space. The value of the line integration of -E.dl form infinity to l=0 centre of ring is in volt is..
  • a) +2
  • b) -1
  • c)-2
  • d)zero
Q.13
Two points P and Q are maintained at the potential of 10V and -4V, respectively. The work done in moving 100 electrons from P to Q is [ AIEEE 2009]
  • a) 9.6×10⁻¹⁷ J
  • b) -2.24×10⁻¹⁶ J
  • c) 2.24×10⁻¹⁶J
  • d) -9.6×10⁻¹⁷ J
Q.14
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.15
Four capacitors each of 25 μF are connected as shown in diagram. The DC voltmeter reads 200 volt. The charge on each plate of capacitor will be [AFMC1997]
ch-13_que_no-2_img_no1.png
  • a) 5×10⁻²C
  • b)2× 10⁻²C
  • c)5× 10⁻³ C
  • d) 2× 10⁻³
Q.16
The mean free path of electrons in metal is 4×10⁻⁸ m. The electric field which can give on an average 2eV energy to an electron in the metal will be in units of V/m [ CBSE-PMT 2009]
  • c) 5×107
  • d) 8×107
  • a) 5×10⁻¹¹
  • b) 8×10⁻¹¹
Q.17
The electric intensity due to a dipole of length 10 cm and having a charge of 500µC, at a point on the axis at a distance 20cm from one of the charge in air, is [ CBSE-PMT 2001]
  • a) 6.25×107 N/C
  • b) 9.28×107N/C
  • c) 13.1×1011 N/C
  • d) 20.5×107 N/C
Q.18
The mean free path of electrons in a metal is 4×10⁻⁸ m. The electric field which can give on an average 2eV energy to an electron in metal will be in units of V/m [ CBSE-PMT 2009]
  • c)5×107
  • d)8×107
  • a) 5×10⁻¹¹
  • b) 8×10⁻¹¹
Q.19
An electric dipole , consisting of two opposite charges of 2×10⁻⁶C each separated by a distance 3cm is placed in an electric field of 2×105 N/C. Torque acting on the dipole is .. [ CBSE-PMT 1995]
  • a)12×10⁻¹N-m
  • b) 12×10⁻² N-m
  • c)12×10⁻³ N-m
  • d)12×10⁻⁴ N-m
Q.20
If the potential of a capacitor having capacity 6µF is increased from 10V to 20V, then increase in its energy will be [ CBSE-PMT 1995]
  • a)4×10⁻⁴ J
  • b) 6×10⁻⁴ J
  • c)9×10⁻⁴
  • d)12×10⁻⁶ J
Q.21
Two metal plates having a potential difference of 800V are 2cm apart. It is found that a particle of mass 1.96×10⁻¹⁵ kg remain suspended in the region between the plates. The charge on the particle must be ( e=elementary charge) : [ PET 1999]
  • a) 3e
  • b) 4e
  • c)6e
  • d)8e
Q.22
An electric dipole consists of two opposite charges each of magnitude 1.0µC separated by distance of 2.0cm. The dipole is placed in an external field of 1.0×105N/C. The maximum torque on the dipole is [ CPMT 1990]
  • a) 0.2×10⁻³ N-m
  • b) 1.0×10⁻³ N-m
  • c)2.0×10⁻³ N-m
  • d)4.0×10⁻³ N-m
Q.23
Two point charges 100µC and 5µC are placed at point A and B respectively, with AB=40cm. The work done by the external force in displacing the charge 5µC from B to C where BC=30cm, angle ABC=π/2 and (1/4πεo )=9×109 [ MPPMT 1997]
  • a) 9 J
  • b) (81/20)J
  • c) (9/25)J
  • d) (-9/4)J
Q.24
Capacitance (in F0 of a spherical conductor with radius 1 m is [ AIEEE 2002]
  • a) 1.1×10⁻¹⁰
  • b) 10-6
  • c)9×10⁻⁹
  • d)10-3
Q.25
A 4 µF conductor is charged to 400V and then its plates are joined through a resistance of 1kΩ. The heat produced in the resistance is [ CBSE 1994]
  • a) 0.61 J
  • b) 1.28J
  • c) 0.64J
  • d) 0.32J
Q.26
Two parallel plates, separated by a distance of 5mm, are kept at a potential difference of 50V. A particle of mass 10-15kg and charge 10-11 C enters in it with a velocity 107 m/s. The acceleration of the particle will be [ MPPMT 1997]
  • a) 108 m/s²
  • b) 5 ×105 m/s²
  • c) 105 m/s²
  • d) 2 × 103 m/s²
Q.27
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.28
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.29
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.30
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.31
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.32
in 1g of solid, there are 5×1021 atoms. If one electron is removed from every one of 0.01% of atoms of the solid, the charge gained by the solid is
  • a) +0.08 C
  • b) 0.8C
  • c)-0.08C
  • d)-0.8C
Q.33
A one micro ampere beam of protons with a cross-sectional area of 0.5 sq.mm is moving with velocity of 3×104 m/sec. Then the charge density of the beam is
  • a)6.6 ×10⁻⁹ coulomb per metre3
  • b) 6.6 ×10⁻⁷ coulomb per metre3
  • c)6.6 ×10⁻⁶ coulomb per metre3
  • d)6.6 ×10⁻⁵ coulomb per metre3
Q.34
The two condensers of capacitance 2 and 3µF are in series. The outer plate of the first condenser is at 1000 V and the outer plate of the second condenser is earthed. The potential of the inner plate of each condenser is
  • a) 300 V
  • b) 500 V
  • c) 600 V
  • d) 400 V
Q.35
The area of the plates of parallel plate condenser is 100cmThe paper ( K=2.5) of thickness 0.005 cm is pit in between the plates. If the paper can tolerate a field of 5×107 volts/m, the minimum potential difference up to which the condenser can be charged is
  • a) 2500 Volts
  • b) 7500 Volts
  • c)500 Volts
  • d)10000 Volts
Q.36
The capacitance of a parallel plate capacitor is 2.5µF. When it is half filled with dielectric as shown in the figure, its capacitance becomes 5µF. The dielectric constant of the dielectric is
ch-13_que_no-280_img_no1.png
  • a) 7.5
  • b) 3
  • c) 0.33
  • d) 4
Q.37
In the circuit shown in figure the key is first inserted between points 1 andThen keey is inserted between 1 andThe heat produced in 300Ω resistance is
ch-13_que_no-286_img_no1.png
  • a) 10J
  • b) 6.25 J
  • c)3.75 J
  • d)7.8 J
Q.38
Potential energy of two equal negative point charges 2µC each held apart in air is
  • a)2J
  • b) 2eV
  • c)4J
  • d)0.036J
Q.39
The number of lines of force that radiate outwards from one coloumb of charge is
  • a)9×109
  • c)infinite
  • d)1.13×1011
  • b) 8.85×10⁻¹⁰
Q.40
The electric potential at the surface of an atomic nucleus ( Z=50) of radius 9.0×10⁻¹⁵ m is
  • a) 80V
  • b) 8 ×106V
  • c)9 Volts
  • d)9 ×105 volts
Q.41
Two capacitor 2µF and 4µF are connected in series across 120V supply. The potential across the 2µF capacitor is
  • a) 120 V
  • b) 40 V
  • c)80 V
  • d)60 V
Q.42
A pendulum bob of mass 80mg, carrying a charge of 2×10⁻⁸ C is at rest in a horizontal uniform electric field of 20000 V/m. The tension in the thread of the pendulum and the angle makes with the vertical are
  • a) 9×10⁻⁴ N, tan⁻¹ (1/2)
  • b) 9×10⁻⁴ N, tan⁻¹ (2)
  • c) 9×10⁻³ N, tan⁻¹ (1.5)
  • d) 8×10⁻³ N, tan⁻¹ (1/2)
Q.43
A uniform electric field of 400 V/m is directed at 45° above the x-axis as shown in the figure. The potential difference VA - VB is given given by
ch-13_que_no-375_img_no1.png
  • a)0
  • b)4V
  • c)6.4V
  • d)2.8V
Q.44
Between the plates of a parallel plate capacitor there is a metallic plate whose thickness takes up 0.6 of the capacitor gap. When the plate is absent, the capacitor has a capacity C=20 nF. The capacitor is connected to a d.c voltage source V=100V. The metallic plate is slowly extracted from the gapThe mechanical work performed in the process of extraction is
  • a) 0.35mJ
  • b) 0.25mJ
  • c)0.15mJ
  • d)0.10mJ
Q.45
Two point charges is air at a distance of 20 cm from each other interact with a certain force. At what distance from each other should these charges be placed in oil of relative permitivity 5 to obtain the same force of interaction
  • d)8.94×102 m
  • a) 8.94×10⁻² m
  • b) 0.894×10⁻² m
  • c)89.4×10⁻² m
Q.46
A conductor gets a charged of 60pC when it is connected to a battery of emf 6mV. Then the capacitance of the conductor is ...
  • d)10×10- F
  • a)120×10⁻⁶ F
  • b) 1.2×10⁻⁹ F
  • c)10×10⁻⁹ F
Q.47
Two capacitors 3pF and 6pF are connected in series and a potential difference of 5000V is applied across the combination. They are then disconnected and reconnected in parallel. The potential between the plates is
  • a)2250 V
  • b) 2222 V
  • c)2.25V×106 V
  • d)1.1 ×106V
Q.48
An electric dipole is placed at an angle of 30° with an electric field intensity 2×105 N/C. It experiences a torque equal to 4 Nm. The charge on the dipole ,if the dipole length is 2 cm, is … [ NEET II : 2016]
  • a) 5 mC
  • b) 7 μC
  • c) 8 mC
  • d) 2 mC
0 h : 0 m : 1 s