## electrical

### Electrostatics and Capacitance MCQ With Answers Page - 1

1.
 The force between two charges is 120 N. if the distance between the charges is doubled, the force will be A 60 N B 30 N C 40 N D 15 N Answer : B Explanation :
2.
 The mass of electron is equal to A 1.602 x 10-19 kg B 9.11 x 10-31 kg C 1.673 x 10-27 kg D 9.11 x 10-20 kg Answer : B Explanation :
3.
 The electric field intensity at a point situate d4 meters from a point charge is 200 N/C. if the distance is reduced to 2 meters, the field intensity will be A 400 N/C B 600 N/C C 800 N/C D 1200 N/C Answer : C Explanation :
4.
 Electric intensity (E) at any point in an electric field is equal to A Potential gradient B (potential gradient)2 C (potential gradient)1/2 D (potential gradient)1/3 Answer : A Explanation :
5.
 The lines of the force due to charge particles are A Always straight B Always curved C Sometimes curved D None of the above Answer : B Explanation :
6.
 The electric field at a point situated at a distance d from straight charged conductor is A Proportional to d B Inversely proportional to d C Inversely proportional to d2 D None of the above Answer : B Explanation :
7.
 The direction of electric field due to positive charge is A Away from the charge B Towards the charge’ C Both (a) and (b) D None of the above Answer : A Explanation :
8.
 A field line and an equipotential surface are A Always parallel B Always at 90° C Inclined at any angle θ D None of the above Answer : B Explanation :
9.
 The ability of charged body to exert force on one another is attributed to the existence of A Electrons B Proton C Neutron D Electric field Answer : D Explanation :
10.
 If the sheet of a Bakelite is inserted between plates of an air capacitor, the capacitance will A decrease B increase C remain unchanged D become zero Answer : B Explanation :
11.
 A capacitor stores 0.24 coulombs at 10 volts. Its capacitance is A 0.024 F B 0.12 F C 0.6 F D 0.8 F Answer : A Explanation :
12.
 For making a capacitor, it is better to select a dielectric having A Low permittivity B High permittivity C Permittivity same as that of air D Permittivity slightly more than that of air Answer : B Explanation :
13.
 The units of capacitance are A Volts/coulombs B Coulombs/volts C Ohms D Henry/wb Answer : B Explanation :
14.
 If three 15µf capacitors are connected in series, the net capacitance is A 5 µF B 30 µF C 45 µF D 50 µF Answer : A Explanation :
15.
 If three 10µf capacitors are connected in parallel, the net capacitance is A 20 µF B 30 µF C 40 µF D 50 µF Answer : B Explanation :
16.
 A dielectric material must be A Resistor B Insulator C Good conductor D Semi-conductor Answer : B Explanation :
17.
 The electrolysis capacitor can be used for A D.C only B A.C only C Both D.C as well as A.c D None of this Answer : A Explanation :
18.
 The capacitance of a capacitor is not affected by A Distance between plates B Area of plates C Thickness of plates D All of the above Answer : C Explanation :
19.
 Which of the following is not a vector? A Linear momentum B Angular momentum C Electric field D Electric potential Answer : D Explanation :
20.
 Two metal plates distance “d” apart from a capacitor of value C farads. Another metal plate of thickness d/2 and of the same areas is inserted in between these two plates, capacitance of this three plate capacitor will be A 4 B 2 C 1/2 D 1/4 Answer : B Explanation :
21.
 Electric field inside a hollow metallic charged sphere is A Increasing towards centre B Decreasing towards centre C Zero D None of the above Answer : C Explanation :
22.
 Two plates of parallel plate capacitor after being charges from a constant voltage source is separated apart by means of insulated handles, then the A Voltage across the plates increases B Voltage across the plate decreases C Charge on the capacitor decreases D Charge on the capacitor increases Answer : B Explanation :
23.
 If A.C voltage is applied to capacitive circuit, the alternating current can be flow in the circuit because A Varying voltage produces the charging and discharging currents B Of high peak value C Charging current can flow D Discharge current can flow Answer : A Explanation :
24.
 Voltage applied across a ceramic dielectric produces an electrolytic field 100 times greater than air. What will be the value of dielectric constant? A 50 B 100 C 150 D 200 Answer : B Explanation :
25.
 Which of the following statement is correct? A Air capacitor have a black band to indicate the outside foil B Electrolytic capacitor must be connected in correct polarity C Ceramic capacitors must be connected in the correct polarity D Mica capacitor are available in capacitance value of 1 to 10 µF. Answer : B Explanation :
26.
 The dissipation factor of a good dielectric is A 0.0002 B 0.002 C 0.02 D 0.2 Answer : A Explanation :
27.
 “The total electric flux through any closed surface surrounding charges is equal to the amount of charged enclosed”. The above statement is associated with A Coulomb’s square law B Gauss’s law C Maxwell’s first law D Maxwell’s second law Answer : A Explanation :
28.
 Three capacitor each of the capacity C are given. The resultant capacity 2/3 C can be obtained by using them A All in series B All in parallel C Two in parallel and third in series with this combination D Two in series and third is parallel across this combination Answer : C Explanation :
29.
 For which of the following parameter variation, the capacitance of the capacitor remains unaffected? A Distance between plates B Area of the plates C Nature of dielectric D Thickness of the plates Answer : D Explanation :
30.
 Which of the following statement is true? A The current in the discharging capacitor grows linearly B The current in the discharging capacitor grows exponentially C The current in the discharging capacitor decays exponentially D The current in the discharging capacitor decreases constantly Answer : B Explanation :
31.
 Which of the following expression is correct for di-electric strength? A E=D/e B E= D²/e C E= ∏D D E=∏D² Answer : A Explanation :
32.
 In a capacitor a electric charge is stored in A Metal plates B Dielectric C Both (a) and (b) D None of the above Answer : B Explanation :
33.
 Which of the following material has the highest value of dielectric constant? A Glass B Vacuum C Ceramic D Oil Answer : C Explanation :
34.
 Which of the following capacitors will have the least variation? A Paper capacitor B Ceramic capacitor C Silver plated mica capacitor D None of the above Answer : C Explanation :
35.
 Which of the following statements is incorrect? A The leakage resistance of ceramic capacitors is generally high B The stored energy in a capacitor decreases with reduction in value of capacitance C The stored energy in a capacitor increases with applied voltage D A wire cable has distributed capacitance between the conductors Answer : B Explanation :
36.
 Which of the following capacitors has relatively shorter self-life? A Mica capacitor B Electrolytic capacitor C Ceramic capacitor D Paper capacitor Answer : B Explanation :
37.
 A condenser suitable for D.C only is A Metallic plate variable gang condenser B Metallic paper capacitor C Oil impregnated paper condenser D Poled aluminium electrolytic condenser Answer : D Explanation :
38.
 In a capacitor, the electric charge is stored in A Metal plates B Dielectric C Dielectric as well as metal plates D None of the above Answer : B Explanation :
39.
 Internal heating of a capacitor is usually attributed to A Electron movement B Leakage resistance C Dielectric charge D Plate vibration Answer : B Explanation :
40.
 If the dielectric of the capacitor is replaced by a conducting material A The capacitance value of the capacitor will shoot up to very high value B The capacitor can be stored infinite charge C The plates will get short-circuited D The capacitor will get heated up due to eddy currents Answer : C Explanation :