### Electrostatics Objectives Part 07

121 . An electric field of 100kV/m is the same as 100V/mm

122 . Three capacitors of 1, 2 and 3uf respectively are connected in series to a 60v dc source. How many capacitors will have voltage drop of more than 20v across themselves? One

123 . What is the work done by a constant force F=(3x + 4y)N in moving an object over a straight line path defined by means of the vector R=(-x + 6y + 3z) m? 0

124 . A charge of 75uc is stored in a capacitor. The area of each of the two plates is 300 cm^2. The flux density in milli-coulombs per square meter is 2.5

125 . A cloud is at a potential of 10^6 volts relative to the ground. A charge of 6C is transferred in a lightning stroke between the cloud and the earth. The energy dissipated is 6*10^6 J

126 . An infinite number of charges, each equal to 1q, are placed at n=1,3,9,27,81,….. The electric potential at n=0 will be 3/2q

127. Two spheres of radii R1 and R2 (R2>R1) are connected by a conducting wire. Each of the spheres has been given a charge q. Now potential of both the spheres will be equal

128 . The energy stored in the electric field is proportional to the square of the …., whereas the energy stored in the electric magnetic field is proportional to the square of the voltage, current

29 . Three capacitors having capacitances 2, 5, 10 and 12uf are connected in parallel across 600V mains. The capacitor having least charge will be 2uf capacitor

130. A capacitor having a capacitance of 200uf is connected across 600V main. If the current is kept constant at 0.1A, the time during which current must be maintained in order to charge the capacitor to 600V will be 1.2 minutes

131 . If the dielectric of the capacitor is replaced by a conducting material the plate will get short circuited

132 . In a dielectric the electrons get detached from the atoms under breakdown

133 . At the air dielectric interface normal component of displacement vector and tangential component of electric field are continuous

`134 . What capacitance must be placed in series with a 15uf capacitor to give a total capacitance of 5uf? 7.5uf

135 . The presence of an uncharged conductor near charged one increase the capacity of the charged conductor

A 12uf and 3uf capacitors have been fully charged from voltage sources of 150V and 750V respectively. The terminals of corresponding polarity of these charged capacitors are connected together.

136 . According to the above data, the total charge of the combination will be 4.05uc

137 . According to the above data, the voltage across the terminals of the combination will be 270

138 . According to the above data, the total energy stored will be 0.547J

139 . An uncharged conductor is placed near a charged conductor, then the uncharged conductor gets charged by induction and then attracted towards the charged body

40 . A capacitor has a capacity C, when air is present in the two plates. A dielectric of values k is placed between the plates. The new capacity will be KC