Question 1 :
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 2 :
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 3 :
The energy stored in a capacitor of capacitance C having a charge Q under a potential $$V$$ is

Question 4 :
The energy stored in a capacitor of capacitance $$C$$ having a charge $$Q$$ under a potential $$V$$ is

Question 5 :
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 6 :
If the distance between the place of a parallel plate capacity $$10\;\mu F$$ is doubled, then new capacity will be:

Question 7 :
Which of the following combinations of seven identical capacitors each of 2$$\mu$$F gives a capacitance of 10/11 $$\mu$$F?

Question 8 :
Identify the conductors from the following:&#160;<br/>Eraser, paper, matchstick, copper wire, polythene.<br/>

Question 9 :
A $$1\ \mu A$$ beam of proton with a cross-sectional area of $$0.5\ sq. mm$$ is moving with a velocity of $$3\times 10^4\ ms^{-1}$$. Then charge density of beam is

Question 11 :
The force acting between two point charges kept at a certain distance is $$5$$N. Now the magnitudes of charges are doubled and distance between them is halved, the force acting between them is _________ N.

Question 12 :
<span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small"><p class="wysiwyg-text-align-left">A charge q is enclosed in a cube at its geometrical centre. What is the&#160;electric flux associated with one of the faces of&#160;cube:</p>

Question 13 :
If a conductor has a potential $$ V\neq 0 $$ and there are no charges anywhere else outside, then

Question 18 :
If coil is placed perpendicular to field lines then number of lines passing through coil are :

Question 19 :
Assertion(A): An inductor in a D.C. circuit opposes&#160;both a steady current and a changing current.Reason(R): Induced emf is generated only when&#160;the flux linked with the inductor remains&#160;unchanged.<br/>

Question 20 :
The rate of change of magnetic flux density through a circular coil of area 10 m and number of turns 100 is 10$$^3$$ Wb/m$$^2$$/s. The value of induced emf will be

Question 21 :
Assertion: When the current in a coil changes, it induces a back emf in the same coil. Reason: Emf is a measure of the inertia of the coil against the change of current through it.

Question 22 :
The relation between magnetic susceptibility $${ \chi&#160; }_{ m }$$ and relative permeability $${ \mu&#160; }_{ r }$$&#160;is

Question 25 :
The magnetic moment produced in a substance of 1 g is $$6 \times 10^{-7}\, A-m^2$$. If its density is $$5 \,\,g/cm^3$$, then the intensity of magnetisation in A/m will be :<br/>

Question 26 :
<span class="wysiwyg-font-size-medium"><span class="wysiwyg-font-size-medium"><p class="wysiwyg-text-align-left">Magnetic induction at a point on the axial line ofa short bar magnet is $$B$$ towards East. If the<span class="wysiwyg-font-size-medium"><span class="wysiwyg-font-size-medium">magnet is turned through $$90^o$$<span class="wysiwyg-font-size-xx-small"><span class="wysiwyg-font-size-xx-small"><span class="wysiwyg-font-size-medium"><span class="wysiwyg-font-size-medium">in clock wisedirection, then magnetic induction at the samepoint is (Neglect Earth's magnetic field).</p>

Question 27 :
Which of the following does earth's magnetic field deflect coming from outersphere?

Question 28 :
A bar magnet is released from rest along the axis of a very long, vertical aluminum tube. After sometime the magnet

Question 29 :
There are three resistance $$5\Omega&#160;,6\Omega&#160;$$&#160;and&#160;$$8\Omega&#160;$$&#160;connected in&#160;parallel to a battery of&#160;$$15 V$$&#160;and of negligible&#160;resistance.&#160;The potential drop across $$6\Omega&#160;$$&#160;resistance is:&#160;

Question 32 :
In a potentiometer experiment of a cell of emf 1.25 V gives balancing length of 30 cm. If the cell is replaced by another cell, balancing length is found to be 40 cm. What is the emf of second cell?

Question 33 :
When the temperature of a metallic conductor is increased its resistance :

Question 34 :
A man has five resistors each of value&#160;$$\frac {1}{5}\Omega $$. What is the minimum resistance he can obtain by connecting them ?

Question 35 :
For a given cell, its terminal voltage depends on ____ and _______.<br/>

Question 36 :
If the balance point is obtained at the $$35^{th} cm$$ in a metre bridge theresistances in the left and right gaps are in the ratio of

Question 39 :
In cyclotron, for a given magnet, radius of the semicircle traced by positive ion is directly proportional to ($$v=$$ velocity of positive ion).<br/>

Question 40 :
A moving coil type of galvanometer is basedupon the principle that<br>

Question 41 :
The magnetic field generated along the axis of a solenoid is proportional to:<br/>

Question 42 :
The magnetic field to a small magnetic dipole of magnetic moment$$ M, $$ at distance $$ r $$ from the centre on the equatorial line is given by(in $$ M.K.S. $$ system)

Question 43 :
When a steel core is placed in a solenoid, it acts like an electromagnet. <br>