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| Physics 12th Chapter 12 - Electrostatics Questions Bank |
Physics 12th Chapter 12 - Electrostatics Questions Bank Solved MCQs, Important Short Questions and Long Questions Bank
MCQs
Please select the right answer.
1. Relative permittivity for air is:
2. 1 micro coulomb is equal to
3. 4 µF & 2 µF are connected in series, their equivalent capacitance is
4. A 50µF capacitor has a potential difference of 8V cross it. The charge on the capacitor is
5. A capacitor’s capacitance can be increased by:
6. A charge of 0.10 C accelerated through a potential difference of 1000 volt acquires K.E.
7. A charge of 10and 14.4 are 12 cm apart, the force between them is:
8. A device used for storing charge is called
9. A is applied when the area is:
10. A Particle carrying a charge of 2e falls through potential difference of 3V.The energy acquired by it will be
11. A particle having 2e charge falls through a potential difference of 5V Energy acquired by it
12. A potential difference b/w two points is one volt. The amount of work done in moving a charge of one coulomb from one point to another is
13. A radio tunning capacitor is a:
14. A substance contains:
15. According to gauss’s law , the flux through any closed surface is
16. An ECG records the between points on human skin generated by electric process in the heart
17. An electric field can deflect
18. An electric field can not deflect
19. An electron volt is the unit of a:
20. An example of photoconductor is:
21. An important part of inkjet printer is:
22. An important port of a photocopier is:
23. An inkjet printer uses in its operation:
24. Another name for electric potential energy per unit charge is:
25. Another term used to mean electric lines of force is:
26. Another unit of electric intensity can be expressed as:
27. Capacitance and potential difference are:
28. Capacitance of a parallel plate capacitor depends on
29. Capacitance of a parallel plate capacitor does not depend on
30. Capacitance of a parallel plate capacitor is given by
31. Capacitor is a device used for:
32. Charge on an electron was determined by
33. Charge on an electron was measured by Millikan in
34. Charles Augustus Coulomb measured the force between two charges by
35. Closeness of the electric field lines in the measure of
36. Concept of electric field theory was introduced by
37. Concept of electric field was given by
38. Coulomb multiplied by volt gives the unit will be called:
39. Dielectric is also called
40. E =
41. Electric charge of 100µC is 13cm apart from another charge 16.9µC. The force between them in Newton is
42. Electric field intensity between oppositely charged parallel plates
43. Electric field intensity due to a point charge at distance r is equal to
44. Electric field intensity due to an infinite sheet of charge is given by
45. Electric field intensity inside a hollow charged sphere is
46. Electric flux due to a point charge q present inside a closed surface can be calculated by
47. Electric flux due to point charge is
48. Electric flux is a:
49. Electric flux is given by the formula
50. Electric flux through any surface depend on
51. Electric potential energy per unit charge is also called
52. Electric potential is:
53. Electron energy is one electron volt when it is accelerated through a potential difference of
54. Electron volt is the unit of
55. Energy acquired by it is
56. Energy density in case of capacitor is always proportional to
57. Energy stored in a capacitor is given by the formula
58. Farad =
59. Farad is the unit of:
60. Faraday is a scientist:
61. For a capacitor , the charge per unit volt is called
62. For the computation of electric flux, surface area should be
63. Force between two similar unit charges placed one meter apart in air is
64. Force experienced by a unit positive charge placed at a point in an electric field is known as
65. Free electrons are:
66. Gauss’s law can only be applied to a surface
67. Gauss’s Law can only be applied to:
68. If a charged body is moving against the electric field it will gain
69. If a dielectric is inserted b/w the plates of a charged capacitor, its capacitance
70. If a oil droplet between two oppositely charged parallel plates is suspended then:
71. If a slab of dielectric is inserted b/w the plates of a parallel plate capacitor connected across a battery. its stored energy
72. If an electron is accelerated through a potential difference of one volt it will acquire energy
73. If an electron of charge “e” is accelerated a potential difference V it will acquire energy:
74. If both the magnitude of charge and distance between them is doubled, then coubled, then coulomb's force
75. If the atomic number of copper is 29, the contribution of electrons per atom in the block of copper will be
76. If the distance between the two charge bodies is halved, the force between them becomes:
77. If the distance between the two charged bodies is halved, the force between them becomes
78. If the distance between two charges is doubled, the electric force between them will become
79. If the distance between two charges is doubled, the electric force between them will become
80. If the medium between the charges is not free space then electrostatic force will:
81. If we increase the charge, the capacitance:
82. If we place a dielectric of Ɛr1 between, the charges, then force become equal to
83. In a charged capacitor energy resides in the form of
84. In a charged capacitor the energy resides in
85. In a charged capacitor, the energy is stored due to:
86. In a region where the electric field is zero the electric potential is always:
87. In case of two identical charges placed at certain distance, the electric lines of force are:
88. In = EA cos, the angle is the angle between the field lines and:
89. Intensity of field inside a Hallow charged sphere is:
90. lf a charged body is moved against the electric field, it will gain:
91. Metals are good conductors of electricity because they have
92. Michael Faraday was known by his work on:
93. NC⁻¹ is the Sl unit of:
94. One Electron Volt is equal to
95. Origin of the gravitational and electric forces:
96. Photo copier and inkjet printer are the application of:
97. Photo copier and the inkjet printer are examples of
98. Presence of dielectric always
99. Presence of dielectric between two charges always:
100. Selenium is a
101. Selenium is an insulator in the dark but when exposed to light it becomes
102. Selenium is:
103. SI unit of capacitance is
104. SI unit of charge is
105. SI unit of electric flux is
106. Since selenium becomes conductor in light it is called
107. special dry black powder is spread over the drum of photocopier is called
108. Special organ called Ampullae of lorenzini that are very sensitive to electric field are found in:
109. speed of charging and discharging of a capacitor depends on resistance &
110. The amount of energy acquired or lost by an alpha particle as it moves through potential difference of 1 V is:
111. The branch of physics which deals with the charges at rest:
112. The change of potential w.r.t displacement is called:
113. The charge on the droplet in Millikan experiment is calculated by formula
114. The charge on the electron was measured by Millikan in:
115. The charges on the parallel plates of capacitor possess:
116. The concept of electric field theory was introduced by:
117. The constant of proportionality ""K"" depend upon:
118. The copying process is called
119. The Coulomb force is:
120. The dielectric consists of atoms and molecules which are:
121. The direction of electric intensity is:
122. The direction of field lines around an isolated charge ""-q"" is
123. The direction of field lines due to a charge +q
124. The drum in a photocopier is coated with a layer of:
125. The earth’s potential is considered as:
126. The electric field created by positive charge is
127. The electric field created by positive charge is:
128. The electric field exist around:
129. The electric field lines are closer where the field is:
130. The electric field lines emerge from the charges in:
131. The electric field will be uniform
132. The electric flux is given by the expression:
133. The electric flux through any surface depends upon:
134. The electric force between two charges placed in air is 2N. when placed in a medium of εr=80, the force reduces to
135. The electric intensity at a distance of 1m from the point charge is IBC is:
136. The electric intensity at infinite distance from the point charge is:
137. The electric intensity is a:
138. The electric lines of force are directed away from:
139. The electric lines of force determine the strength of an:
140. The electric potential at a point due to a point charge is given by V=
141. The electrostatic force of repulsion between two electrons at a distance 1m is:
142. The electrostatic force of repulsion between two electrons at a distance of one meter is
143. The fact that Electric Field exists in space around an electrical charge is
144. The force b/w two point charges in air or vacuum is F. if air or vacuum is replaced by an insulator of relative permittivity εr the force b/w charges
145. The force between two similar unit charges placed one meter apart in air is:
146. The force experience by unit positive charge placed at a point in an electric field is called:
147. The force in medium of relative permittivity εr is given by
148. The force per unit charge is called:
149. The force per unit charge is known as
150. The formula for energy density is valid for only:
151. The inkjet printer ejects a thin stream of:
152. The interior of a hollow charged metal sphere is a region which is:
153. The interior of a hollow charged sphere is a:
154. The magnitude of charge on an electron is
155. The magnitude of electric field between two point can be calculated by the relation
156. The Millikan’s experiment apparatus also contains:
157. The minimum charge on an object can not be less than
158. The minimum charge on any electron be less than:
159. The negative of the potential gradiant is:
160. The number of electric field lines passing through a certain element of area is called:
161. The number of electric lines of force passing through certain area is known as:
162. The number of electrons in one coulomb charge is equal to:
163. The number of free electrons in one coulomb charge is
164. The photo copying process is called
165. The potential at a point situated at a distance of 50 cm from a charge of 5gc is:
166. The potential of all the points of a equi potential surface is
167. The practical application of electrostatic is:
168. The relation (∆V/∆r=V/d) represents
169. The relative permitivity of air is:
170. The SI unit of charge is:
171. The SI unit of charge is:
172. The SI unit of electric field intensity(strength) E is
173. The SI unit of electric flux is:
174. The SI unit of potential difference is
175. The SI units of Coulomb's constant are
176. The SI units of permitivity are:
177. The space around the charge within which other charges are influenced by it is called:
178. The surface charge density is defined as:
179. The symbol e r denotes for:
180. The term RC has the same unit as that of (RC= )
181. The toner of the printer is given
182. The unit of electric intensity is:
183. The unit of energy density of electric field is
184. The unit of Fe/Fg is:
185. The value of capacitance depends upon:
186. The value of K depends upon:
187. The value of K in SI system of units:
188. The value of permitivity of free space:
189. The value of relative permittivity for all the dielectrics other than air or vacuum is always
190. The value of r for various dielectrics will always:
191. The voltage across the capacitor at any instant can be obtained by:
192. The word ""Xerography"" means:
193. The work done in moving a positive charge on an equipotential surface is:
194. Three capacitors of capacitance 1µ farad each are connected in series. Their equivalent capacitance is
195. Two 50 µF capacitors are connected in parallel their equivalent capacitance
196. Two charges 1 c and 5 c separated by 20 cm, the ratio of electrical forces acting on them will be:
197. Two opposite point charge of same magnitude separated by distance 2d, electric potential mid-way between them is:
198. Two oppositely charged balls A & B attract third ball C when placed near them turn by turn. Then ball C must be
199. Two point charges +2C and +6C repel each other if a charge 0f -2C is given to each of them then electrostatic force between them is
200. Unit of capacitance is
201. Unit of electric field intensity is
202. Value of dielectric constant for air or vacuum is
203. Value of Ɛr for air is;
204. What is standard to measure the relative permittivity:
205. What will be the electrostatic force of repulsion between two electrons at I metre :
206. What will be the potential on its surface will be:
207. When a dielectric is placed in an electric field it
208. When a surface is held parallel to E then flux is
209. When current of one ampere is flowing across any cross-section of wire in one second, then the quantity of charge is said to be:
210. When dielectric is placed between the plates it decrease the:
211. When placed in a medium of r = 80, the force will be reduced to:
212. When separated by a medium of relative permittivity 2 the between them becomes
213. When the field is strong, the lines of force are:
214. When the medium is insulator the electrostatic force between the charges is:
215. Which of the following can be taken as measure of electric field intensity
216. Which of the following forces are conservative:
217. Which of the following forces is only repulsive:
218. Which of the following statement is correct:
219. Which one is a photo conductor?
220. Work done in bringing a unit positive charge from infinity to that point in an electric field is:
221. Work done in moving a charge (unit positive charge) from one point to another against the electric field is measure of:
222. Xerography means
Short Questions
1. A charge particle is placed in an electric field what is the force on the particle if the charge on the particle is doubled ?
2. Can there be a potential difference between two conductors that carry like charges of the same magnitude?
3. Can two equipotential surfaces inter-sect each other?
4. Convert joule in electron volt?
5. Define an electric field ?
6. Define capacitance of the capacitor?
7. Define conductor ?
8. Define dielectria constant for capacitors.Also write its unit?
9. Define dielectric constant &, for capacitors ?
10. Define electric dipole moment?
11. Define electric field intensity and also write
12. Define electric flux ?
13. Define electric potential?
14. Define electrical potential?
15. Define farad ?
16. Define potential difference between two points.Give its unit and define it?
17. Define potential difference between two points?
18. Define relative permittivity or dielectric
19. Define time constant of a capacitor ?
20. Define volt?
21. Describe five properties of electric field lines?
22. Describe the charging of a capacitor by battery assuming the positive charge as transferred?
23. Describe the conditions for the maximum
24. Describe the factors upon which the capacitance of a capacitor depends?
25. Describe the force or force on a positive point charge when placed between parallel plates? a) With similar and equal charges. b) With opposite and equal charges.
26. Describe the principle of Millikan’s oil drop method?
27. Describe the working of inkjet printer briefly?
28. Do electrons tend to go to region of high potential or of low potential?
29. Electric lines of forces never cross?
30. Explain briefly the term’’ potential gradient?
31. Explain the term potential gradient?
32. Explain the working of inkject printer ?
33. Gauss’s law has been derived by assuming that the charge enclosed by a closed surface is positive.If q negative what happens to the field lines?
34. Generally bow many methods are used for connecting capacitors ?
35. Give some important properties of electric
36. Give the SI unit of absolute potential and
37. How can we shield any apparatus from electric field?
38. How can you identify that which plate of a capacitor is positively charged ?
39. How can you increase the capacity of a capacitor?
40. How solids get charge ?
41. How would you show that the electrostatic force on a charged object is independent of its mass?
42. If a point charge q of mass m is released in a non-uniform electric field will it make a rectilinear motion?
43. If area A is inclined at an angle e with the field lines, then what is the flux ?
44. If the absolute potential at a point is zero what can you say about the electric intensity there?
45. If the distance between two point charges is halved,what will happen to the force between them?
46. In a charged capacitor which form of the energy stored ?
47. Is Coulomb’s electrostatic interaction consistent with Newton’s third law?
48. Is E necessarily zero inside a charged rubber balloon if balloon is spherical?Assume that charge is distributed uniformly over the surface?
49. Is electron volt (eV) a unit of potential difference or energy?
50. Is it possible for an electrostatic field lines to intersect?
51. Is it true that Gauss's law states that the total number of lines of forces crossing any closed surface in the outward direction is proportional to the net positive charge enclosed with in surface?
52. Prove that 1volt/1meter = 1Newton /1Coulomb ?
53. Show that 1 ev = 6 x 10⁻¹⁹ J?
54. State Coulomb’s law?
55. State Gauss's law?
56. Suppose that you follow an electric field line due to a positive charge.Do electric field and the potential increase or decrease?
57. The potential is constant throughout a given region of space.Is the electrical field zero or nonzero in this region?
58. What a charge produces in the space surrounding it?
59. What are electric field lines, give their importance ?
60. What are the factors upon which the electric flux depends?
61. What do you under stand by electric field lines?
62. What happens to a capacitance in case of presence of any medium between the plates of a capacitor ?
63. What happens when a dielectric material is placed in an electric field ?
64. What is a capacitor?
65. What is an electric dipole ?
66. What is an electric field?
67. What is an electric force ?
68. What is an ideal electric dipole ?
69. What is an insulator?
70. What is Capacitor?
71. What is coulomb's force in a medium of
72. What is electrostatics?
73. What is Farad?Define it?
74. What is Gaussian surface ?
75. What is meant by electric polarization?
76. What is one electron-volt ?
77. What is Physics ?
78. What is the angle which the lines of force make with the surface of a good conductor ?
79. What is the capacitance of a parallel plate capacitor ?
80. What is the difference between electrical potential energy and the electrical potential difference?
81. What is the effect of medium on coulomb's force ?
82. What is the effect of medium between the charges upon coulomb’s force?
83. What is the electric field on a sphere of radius r1 placed inside a concentric sphere of radius r.There is a charge bigger sphere.Give brief reason for your answer?
84. What is the electric flald Intensity between two oppositely charged parallel plates ?
85. What is the electric flux through a closed surface with a charge q placed at its centre ?
86. What is the electric intensity of field inside a
87. What is the law of electrostatics ?
88. What is the result of Millikan's oil drop method ?
89. What is the SI unit of capacitance ?
90. What is the SI unit of electric flux ?
91. What is the unit of potential difference?
92. What is the value of permittivity of free space & in Sl units ?
93. What is the value of relative permittivity of
94. What is the value of relative permittivity of glass ?
95. What is the value of relative permittivity of vacuum ?
96. What is time constant of a capacitor?
97. What is xerography ?
98. What is xerography or photocopier ?
99. What will be flux through a surface placed at right angle to the electric field?
100. What will be the flux through a closed surface which does not contain any charge?
101. When we move in an electric field the potential changes at the rate of 10 v/m.What is the electric intensity?
102. Whether coulomb's law enables us to calculate the magnitude or direction of the electric
103. Whether potential difference is a scalar quantity ?
104. Whether potential is a vector quantity ?
105. Whether the electric field intensity is a scalar or vector quantity ?
106. Whether the electric flux is a vector quantity?
107. Whether the electrostatic force. is conservative force ?
108. Whether the gravitational constant 'G' is larger as compared to electric constant 'K' ?
109. Whether the gravitational force is conservative force ?
110. Whether the gravitational force is weak force as compared to electrostatic force ?
111. Who determined the charge on an electron ?
112. Why does each plate of a capacitor receive same amount of change during charging of a capacitor?
113. Why does each plate of a capacitor receives same amount of charge during charging a capacitor?
114. Why does spherical symmetry of a sphere shell demand the E due to charge q ar the center of shere be constant over the surface?
115. Why does the charge given to the conductor tend to reside on the surface of the conductor ?
116. Write any application of electric field lines?
117. Write any one use of charging and discharging of a capacitor ?
118. Write any two difference between gravitational and electric forces ?
119. Write down the relation for absolute potential?
Long Questions
1. State and explain coulomb’s law.
2. Describe the fields of force.
3. What is the vector form of Coulomb’s law?
4. What is the effect of medium on the Coulomb’s force?
5. Define electric field and electric field intensity. Also calculate the electric field intensity due to a point charge.
6. Describe the electric field lines. Write some properties of electric lines of force.
7. Describe xerography in detail.
8. What is the inkjet printers?
9. Define electric flux. Also discuss its particular cases.
10. Calculate the electric flux through a surface enclosing a charge.
11. Calculate the intensity of field inside a Hollow charged sphere.
12. Calculate the electric intensity due to an infinite sheet of charge.
13. Calculate the electric intensity between two oppositely charged parallel plates.
14. Describe electric potential and potential difference with its units.
15. Explain the electric field as potential gradient.
16. Define absolute potential. Also calculate the potential at a point due to a point charge.
17. Compare the electric and gravitational forces.
18. How Millikan’s method can be used to determine the charge?
19. Define capacitor and what is the parallel plate capacitor? Also define capacitance with its units.
20. Describe the capacitance of a parallel plate capacitor. Also discuss the effect of medium on capacitance.
21. What is the electric polarization of dielectrics?
22. Calculate the energy stored in a capacitor.
23. Describe the charging and discharging of a capacitor.
24. Compare magnitudes of electrical and gravitational force exerted on an object (mass 20 g charge = 20 micro C) by an identical object that is placed 10 cm from the first. (G = 6.67 x 10⁻¹¹ Nm²kg⁻²)
25. A point charge q = -8 x 10⁻⁸ C is placed at the origin. Calculate electric field at a point 2 m from the origin on the z axis?
26. Determine the electric field at the position r = (4i + 3j) m caused by as point charge q = 5 x 10⁻⁶ placed at origin.
27. Two point charges, q1 = -1 x 10⁻⁶ C and q2 = 4 x 10⁻⁶ C, separated by a distance of 3 m. Find and justify the zero field location.
28. Find the electric field strength required to hold suspended particle of mass 1 x 10⁻⁶ kg and charge 1 micro C between two plates 10 cm apart.
29. A particle having a charge of 20 electrons on it falls through a potential difference of 100 volts. Calculate the energy acquired by it in electron volts (eV).
"30. In Millikan’s experiment, oil droplets are introduced into the space between two flat horizontal plates, 500 mm apart. The plate voltage is adjusted to exactly 780 Volts so that the droplet is held stationary. The plate voltage is switched off and the selected droplet is observed to fall a measured distance of 50 mm in 12 s. Given that the density of the oil used is 9000kgm(-3), and the viscosity of air at laboratory temperature is 8 x 10⁻⁵ Nm⁻²s, calculate:
(a) the mass, and
(b) the charge on the droplet (assume g = 9.8 ms⁻²)"
"31. A proton placed in uniform electric field of 5000 NC⁻¹ directed to right is allowed to go a distance of 10 cm from A to B. Calculate:
(a) Potential difference between the two points
(b) Work done
(c) The change in Potential Energy of the proton
(d) The change in Kinetic Energy of the proton
(e) Its velocity (mass of proton is 67 x 10²⁷ kg)"
32. Using zero reference point at infinity, determine the amount by which a point charge of 4 x 10⁻⁸ C alters the electric potential at point 2m away, when (a) charge is positive (b) charge is negative
"33. In Bohr’s atomic model of hydrogen atom, the electron is in an orbit around the nuclear proton at a distance of 5.29 x 10⁻¹¹ m with a speed of 2.18 x 10⁶ ms⁻¹. Find
(a) The electric potential that a proton exerts at this distance.
(b) Total energy of the atom in eV.
(c) The ionization energy for the atom in eV."
34. The electrostatic flash attachment for a camera contains a capacitor for storing energy used to produce the flash. In one such unit, the potential difference between the plates of a 750 micro Farad capacitor is 330 Volt. Determine the energy that is used to produce the flash.
35. A capacitor has a capacitance of 2.5x 10⁻⁸ Farad. In the changing process, electrons removed from one plate and placed on the other one. When the potential difference between the plates is 450 volt, how many electrons have been transferred? (e = 60 x 10⁻¹⁹ Coulomb)