Question 2 :
A drop of oil of density $$\rho$$ and radius $$r$$ carries a charge $$q$$ when placed in an electric field $$E$$, it moves upwards with a velocity $$v$$. If $${\rho}_{0}$$ is the density of air, $$\eta $$ be the viscosity of the air, then which of the following force is directed upwards?
Question 3 :
Identify the conductors from the following: <br/>Eraser, paper, matchstick, copper wire, polythene.<br/>
Question 4 :
A plane area of $$100\ {cm}^{2}$$ is placed in uniform electric field of $$100\ N/C$$ such that the angle between area vector and electric field is $$60^o$$. The electric flux over the surface is
Question 6 :
A hollow conducting sphere of charge does not have electric field at
Question 7 :
Electric charge is due to the loss or gain of .............
Question 8 :
Two equations are given below:<br>A) $$\oint \overline {E} .d\overline {A} = \dfrac {Q}{E_{0}}$$ B) $$\oint \overline {B} . d\overline {A} = 0$$
Question 9 :
Find out on which of following factors does strength of the force between charged particles depend.<br/>
Question 10 : <p><span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small">A body has a charge of <font size="3">$$9.6 \times 10^{-20}$$</font><span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small">coulomb. It is :</p>
Question 11 :
A single electron has change $$\displaystyle \left | e \right |= 1.6 \times 10^{-19} C$$. If the current passing through a conducting wire is $$0.32 A$$, how many electrons would pass through the wire In one hour?
Question 12 :
A hemisphere body of radius $$R$$ is placed in a uniform electric field $$E$$. What is the flux linked with the curved surface if the field is perpendicular to the base?
Question 13 :
A positive charge q is placed in a spherical cavity made in a positively charged sphere. The centres of sphere and cavity are displaced by a small distance $$\vec l$$. Force on charge q is:<br/>
Question 14 : <span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small"><p class="wysiwyg-text-align-left">A large flat metal surface has uniform charge density $$+\sigma $$. An electron of mass $$m$$ and charge $$e$$ leaves the surface at point A with speed $$v$$, and return to it at point B. The maximum value of AB is:<br/></p>
Question 15 :
Let $$E_1(r), E_2(r)$$ and $$E_3(r)$$ be the respective electric fields at a distance r from a point charge Q, an infinitely long wire with constant linear charge density $$\lambda$$, and an infinite plane with uniform surface charge density $$ \sigma $$. lf $$E_1(r_0) = E_2(r_0) = E_3(r_0)$$ at a given distance $$r_0$$, then :<br/>
Question 16 :
A 16 pF capacitor is connected to 70 V supply. The amount of electric energy stored in the capacitor is:
Question 17 :
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 18 :
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 19 :
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 20 :
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 21 :
The energy stored in a capacitor of capacitance C having a charge Q under a potential $$V$$ is
Question 22 :
$$R=100\ k\Omega$$ 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 23 :
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 24 :
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 25 : <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 26 :
When a metal plate is introduced between the two plates of a charged capacitor and insulated from them, then<br>
Question 28 :
Three charges $$2q, -q,$$ and $$-q$$ are located at the verticesof an equilateral triangle. At the center of the triangle,
Question 29 :
Three point charges $$Q,4Q$$ and $$16Q$$ are placed on a straight line $$9cm$$ long. Charges are placed in such a way that the system has minimum potential energy. Then<br>
