Question 1 : <span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small"><p class="wysiwyg-text-align-left">Select correct Statements : </p><p class="wysiwyg-text-align-left">a) Charge cannot be isolated</p><p class="wysiwyg-text-align-left">b) Repulsion is the sure test to know the presence of charge</p><p class="wysiwyg-text-align-left">c) Waxed paper is dielectric in paper capacitor</p><p class="wysiwyg-text-align-left">d) Variable capacitor is used in tuning circuits in radio</p>
Question 2 : <p class="wysiwyg-text-align-left"><span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small">Three capacitors $$2\mu F, 3\mu F$$ and $$5\mu F$$ <span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small">are connected in parallel. The capacitance of the combination:</p>
Question 3 : <p class="wysiwyg-text-align-left">There are $$10$$ condensers each of capacity $$5\; \mu F$$. The ratio of minimum to maximum capacity obtained from these condensers will be :<br/></p>
Question 4 : <p class="wysiwyg-text-align-left"><span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small">To obtain $$3 \mu F$$<i><span class="wysiwyg-font-size-medium"><span class="wysiwyg-font-size-medium"> </i><span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small">capacity from three capacitors of <span class="wysiwyg-font-size-medium"><span class="wysiwyg-font-size-medium"><span class="wysiwyg-font-size-small">$$2 \mu F$$<i><span class="wysiwyg-font-size-medium"><span class="wysiwyg-font-size-medium"> </i><span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small">each, they will be arranged as follows:</p>
Question 5 :
From a supply of identical capacitors rated $$8\ \mu F, 250\ V$$, the minimum number of capacitors required to form a composite $$16\ \mu F, 1000\ V$$ capacitor is:
Question 6 :
Two capacitors of $$1\mu F$$ and $$2\mu F$$ are connected in series and this combination is changed upto a potential difference of $$120$$ volt. What will be the potential difference across $$1 \mu F$$ capacitor:
Question 7 :
Four capacitors of equal capacitance have an equivalent capacitance $${ C }_{ 1 }$$ when connected in series and an equivalent capacitance $${ C }_{ 2 }$$ when connected in parallel. The ratio $$\dfrac { { C }_{ 1 } }{ { C }_{ 2 } } $$ is
Question 8 :
For capacitors in the series combination, the total capacitance C is given by<br/><br/>
Question 9 :
Find the total capacitance for three capacitors of $$10$$f,$$15$$f and $$35$$f in parallel with each other?
Question 10 :
Two capacitors of capacity $$C_1$$ and $$C_2$$ are connected in parallel, then the equivalent capacity is:
Question 11 : <span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small"><p class="wysiwyg-text-align-left">In a charged capacitor the energy is stored in<b>:</b></p><b><span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small"></b>
Question 12 :
Two parallel-plate of capacitor have charges +Q and -Q and potential difference $$\triangle V$$ due to charging, Now the capacitor is disconnected then the potential difference and the stored electrical potential energy is:
Question 13 :
A potential difference of $$\Delta V$$exists between two plates of a parallel-plate capacitor with capacitance C . A dielectric with a dielectric constant of kis then placed between the plates of the capacitor. What is the energy stored in the capacitor?
Question 14 :
If the charge on the condenser of $$10\mu F$$ is doubled, then the energy stored in it becomes ____________.
Question 15 :
A capacitor having capacity of $$2.0\mu F$$ is charged to $$200\ V$$ and then the plates of the capacitors are connected to a resistance wire. The heat produced in joule will be :
Question 16 :
The capacity of a condenser is 20$$\mu F$$ $$\displaystyle $$ and the potential is 20 V. The energy released an discharging it fully will be
Question 17 :
A $$2 \mu F$$ capacitor is charged to $$100 V$$ and then its plates are connected by a conducting wire, the heat produced is :
Question 18 :
The energy stored in a capacitor of capacitance C having a charge Q under a potential $$V$$ is
Question 19 :
The amount of work done is increasing the voltage across the plates of a capacitor from $$5V$$ to $$10V$$ is $$W$$. The work done in increasing it from $$10V$$ to $$15V$$ will be :
Question 20 :
The potential energy of system of two equal negative point charges of $$2\mu C$$ each held 1 m apart in air is ($$k = 9 \times 10^9\, SI \,unit$$)
Question 21 :
The capacitance of a variable capacitor joined with the battery of $$100$$V is changed from $$2\mu F$$ to $$10\mu F$$. What is the change in the energy stored in it?
Question 22 :
The capacity of a condenser is $$4 \times 10^{-6}$$ farad and its potential is 100 volts. The energy released on discharging it fully will be
Question 23 :
The energy stored in a capacitor of capacitance $$C$$ having a charge $$Q$$ under a potential $$V$$ is
Question 24 :
A capacitor of capacity C$$_{1}$$ charged up to V volt and then connected to an uncharged capacitor C$$_{2}$$.Then final P.D. across each will be:
Question 25 :
$$R=100\ k\Omega$$ and $$C=1\ \mu F$$ are connected in a series with a $$12\ volt$$ battery. What is the maximum energy stored in the capacitor:
Question 26 :
A metallic sphere of radius $$18cm$$ has been given a charge of $$5\times { 10 }^{ -6 }C$$. The energy of the charged conductor is :
Question 27 :
A 16 pF capacitor is connected to 70 V supply. The amount of electric energy stored in the capacitor is:
Question 28 :
If a capacitor having capacitance of $$1200\mu F$$ is charged at a uniform rate of $$100\mu C/s$$, what is the time required to increase its potential by $$20$$ volts?
Question 29 :
A parallel plate capacitor of $$1\mu F$$ capacity is discharging through a resister. If its energy reduces to half in one second. The value of resistance will be?
Question 30 : <span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small"><p class="wysiwyg-text-align-left">The energy stored in a sphere of $$10$$ cm radius when the sphere is charged to a potential difference of $$300$$ V is</p>
Question 31 :
A capacitor of $$10\  \mu F$$ is connected to a $$10\ V$$ cell. The maximum charge on the capacitor will be:
Question 32 :
Two point charges $$q$$ and $$q_1$$ are placed at distance $$r$$ apart. A dielectric sheet of dielectric constant $$k$$ and thickness $$t$$ is placed in between. Find the force between the two charges :<br/>
Question 33 :
Calculate the area of the plates of a one farad parallel plate capacitor if separation between plates is 1 mm and plates are in vacuum :<br/>
Question 34 :
Capacity of a capacitor is 48 $$\mu F$$. When it is charged from 0.1 C to 0.5 C, change in the energy stored is :<br/>
Question 35 :
The conducting sphere of radii $$r_{1}$$ and $$r_{2}$$ are at the same potential. What is the ratio of their charges?
Question 36 :
Consider the two idealised systems<br/>(i) a parallel plate capacitor with large plates and small separation and<br/>(ii) a long solenoid of length $$L >> R$$, radius of cross - section.<br/>In (i) $$\bar{E}$$ is ideally treated as a constant between plates and zero outside. In (ii) magnetic field is constant inside the solenoid and zero outside. These idealised assumptions, however, contradict fundamental laws as below.
Question 37 :
A battery is used to charge a parallel plate capacitor till the potential difference between the plates becomes equal to the electromotive force of the battery. The ratio of the energy stored in the capacitor and the work done by the battery will be :<br/>
Question 38 :
Two parallel plate air capacitors are constructed,one by a pair of iron plates and the second by a pair of copper plates of same area and same spacings. Then:
Question 39 :
A capacitor of $$50 \mu F$$ is connected across a $$200$$ volt supply. The charge that it would take is
Question 40 : <span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small"><p class="wysiwyg-text-align-left">A parallel plate capacitor is charged and the charging battery is then disconnected. If the plates of the capacitor are moved further apart by means of insulating handles , then:</p>
Question 41 : <p class="wysiwyg-text-align-left"><span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small">Two electric charges of $$9\mu C$$<i><span class="wysiwyg-font-size-medium"><span class="wysiwyg-font-size-medium"> </i><span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small">and $$-3\mu C$$ <span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small">are placed $$0.16m$$ apart in air. There will be a point P at which electric potential is $$zero$$ on the line joining the two charges and in between them. <span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small">The distance of P from $$9\mu C$$ <span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small">charge is:</p>
Question 42 :
Two equal charges A and B each of $$1/3 \times 10^{-6}C$$ are placed 200 cm apart in air. A particle carrying a charge of $$-1/3 \times 10^{-6}C$$ is projected along the perpendicular bisector from the point O midway between A and B with a kinetic energy of $$10^{-3} J$$. Before the particle starts to return it will cover a distance
Question 43 :
A capacitors is charged to store an energy $$U$$. The charging battery is disconnected. An identical capacitor is now connected to the first capacitor in parallel. The energy in each of the capacitors is<br/>
Question 44 :
Two charges of equal magnitude $$q$$ are placed in air at a distance $$2a$$ apart and third charge $$-2q$$ is placed at mid-point. The potential energy of the system is ($${\varepsilon}_{0} =$$ permittivity of free space) :
Question 45 :
Two plates are placed at a separation of 2 cm. An electron placed at the perryferry of one plate reaches the second plate in 2 microsecond. Calculate the inner charge density of the surface assuming the case of infinite plate.
Question 46 :
A parallel plate capacitor without any dielectric within its plates, has a capacitance C, and is connected to a battery of emf V. The battery is disconnected and the plates of the capacitor are pulled apart until the separation between the plates is doubled. What is the work done by the agent pulling the plates apart, in this process?
Question 47 :
Two small identical metal balls $$A$$ and $$B$$ of radius '$$r$$' are placed apart. The distance between centre of balls is '$$a_0$$'. The net potential of ball $$A$$ is $$V_1$$ and that of $$B$$ is $$V_2$$. Let $$q_1$$ and $$q_2$$ are the charges on balls $$A$$ and $$B$$ respectively. Then the charges on A and B are (given $$r < < a_0)$$
Question 48 :
A particle A of mass m and charge Q moves directly towards a fixed particle B, which has charge Q. The speed of A is v when it is far away from B. The minimum seperation between the particles is proportional to
Question 49 :
A capacitor is charged and battery is disconnected .Now the distance between the plates is increased slightly
Question 50 :
Electric potential due to a point charge $$q$$ at a distance $$r$$ from is given by
Question 51 :
Two identical particles of mass $$m$$ carry charge $$Q$$ each. Initially one is at rest on a smooth horizontal plane and the other is projected along the plane directly towards first particle from a large distance with speed $$v$$. The closest distance of approach will be<br>
Question 52 :
The electric potential at a certain distance from a point charge $$Q$$ is $$810 V$$ and electric field is $$300 N/C$$. The minimum speed with which a particle of charge $$-Q$$ and mass $$m = 6 \times 10^{-16} kg$$ should be projected from that point so that it moves into the field free region is:
Question 53 :
A particle A has charge +q and a particle B has a charge +9q with each of them having the same mass m.If both the particles are allowed to all from rest through the same potential difference, then the ratio of their speed is
Question 54 :
A parallel plate condenser with a dielectric of dielectric constant $$K$$ between the plates has a capacity $$C$$ and is charged to a potential $$V$$ volt. The dielectric slab is slowly removed from between the plates and then reinserted. The net work done by the system in this process is :<br>
Question 55 :
The force experienced by a charged particle of charge $$q$$ at $$(1,1,1)$$ is
