Flux as the Flow

Q. an electric dipole is placed at an angle 60^{0 }with an electric field of strength 4×10^{5 }N/C. it experiences a torque equal to 8\sqrt3 Nm. calculate the charge on the dipole, if dipoleis of length 4cm (1) 10^{-1 }C (2)10^{-2} C (3)10^{-3 }C (4) 10^{-4}

Q.

If the electric Field is given by 6i+3j+4k calculate the electric flux through a surface of area 20 units lying in Yz plane

Q.

A charge q is placed at the center of a cube of side l. What is the electric flux passing through two opposite faces of the cube?

Q. Point charges +4q, -q, +4q are kept on the x-axis at points x=0,
x=a, x=2a respectively...

OPTIONS
1. Only -q is in stable equilibrium
2. All the charges are in stable eqbm
3.all the charges are in unstable eqbm
4. None of the charges are in eqbm

Sir , please ..do provide the explanation or steps alongwith the right option ..so it's easily understood.

Q. At each of the four corners of a square of side A, a charge +q is placed freely. What charge should be placed at centre of square so that the whole system be in equilibrium?

Q. What is the net flux of the uniform electric field of Exercise 1.15 through a cube of side 20 cm oriented so that its faces are parallelto the coordinate planes?

Q. Two identical point charges are placed at a separation of d. P is a point on the line joining the charges, at a distance x from any one charge. The field at P is E. E is plotted against x for values of x from close to zero to slightly less than d. Which of the following represents the resulting curve?

1. 
2. 
3. 
4. 

Q.

If the electric flux entering and leaving an enclosed surface respectively are ${\Phi }_1$ and ${\Phi }_2$, the electric charge inside the surface will be

1. $\frac{({\varphi }_2-{\varphi }_1)}{{\epsilon }_o}$

2. $\frac{({\varphi }_2+{\varphi }_1)}{{\epsilon }_o}$

3. $\frac{({\varphi }_1-{\varphi }_2)}{{\epsilon }_o}$

4. ${\epsilon }_o({\varphi }_2-{\varphi }_1)$

Q. For a finite line charge, find the electric field in a direction parallel to the axis of the line charge at point $\text{P}$.

1. $3.4\text{N/C}$
2. $4.4\text{N/C}$
3. $5.4\text{N/C}$
4. $6.4\text{N/C}$

Q. Electric field, due to an infinite line of charge, as shown in figure at a point $P$ at a disatnce $r$ from the line is $E$. If one half of the line of charge is removed from either side of point $A$, then

1. electric field at $P$ will have magnitude $\frac{E}{2}$
2. electric field at $P$ in $X$ direction will be $\frac{E}{2}$
3. electric field at $P$ in $Y$ direction will be $\frac{E}{2}$
4. none of these

Q. Based on the given graph between electric field $\left(E\right)$ and distance $\left(r\right)$ from axis of the infinite uniformly charged solid non-conducting cylinder, the charge density is
[$R$ is radius of cylinder]

1. $0.8\times {10}^{-11}{\text{C/m}}^3$
2. $1.8\times {10}^{-11}{\text{C/m}}^3$
3. $2.8\times {10}^{-11}{\text{C/m}}^3$
4. $3.8\times {10}^{-11}{\text{C/m}}^3$

Q.

All properties of the charge

Q. A point charge $q$ is placed near to an infinitely large plane. Find flux through the plane.

1. $\frac{q}{{\in }_0}$
2. $\frac{q}{4{\in }_0}$
3. $\frac{q}{6{\in }_0}$
4. $\frac{q}{2{\in }_0}$

Q. the electric field at a point A is perpendicular to the direction of dipole moment P of a short electric dipole. THe angle theta is equal to

Q. Three charges +Q1, +Q2 and Q are placed on a straight line such that Q is somewhere in between +Q1 and+Q2. If this system of charges is in equilibrium, what should be the magnitude and sign of charge q?(in terms of Q1 and Q2)

Q. Three charges q1= 1 microcoulomb, q2= -2 microcoulomb and q3=3 microcoulomb are placed on the vertices of an equilateral triangle of side 1 metre. Find the net force acting on the charge q1 and also the angle with the line joining q1 and q2

Q. two parallel plates have charges Q1 and Q2 on them and the capaci†an ce is C. the potential difference between them i

Q. The figure shows the path of a positively charged particle 1 through a rectangular region of uniform electric field (region shown with dotted lines) as shown in the figure. What is the direction of electric field and the direction of deflection of particles 2, 3, 4?

1. Top, down, top, down
2. Top, down, down, top
3. Down, top, top, down
4. Down, top, down, down

Q.

If only one charge is available can it itself be used to obtain a charge many times greater than itself in magnitude?

Q. Electric field at an axial point due to a finite line charge varies as $E=\frac{90}{x^2+4x}$, where $x$ is in metres and is the distance along axial line from one of the ends. The total charge on the line is

1. $10\text{nC}$
2. $11\text{nC}$
3. $12\text{nC}$
4. $13\text{nC}$

Q. Find the electric field at the center of a uniformly charged hemispherical shell of surface charge density sigma USING GAUSS LAW.

Q. A uniform electric field exists in x-y plane. The potential of points A(2m, 2m), B (-2m, 2m) and C (2m, 4m) are 4V , 16V and 12V respectively. The electric field is :

Q. The ratio of electric potential on a equatorial and a axial point of short dipole will be 1 0

Q. An average induced emf of $0.20\text{V}$ appears in a coil when the current in it is changed from $5\text{A}$ in one direction to $5\text{A}$ in the opposite direction in $0.20\text{s}.$ The self-inductance $\left(\text{in mH}\right)$ of the coil is
(Give integer value only)

Q. A particle having a charge of 10 microcoulomb and mass 1 microgram moves in a horizontal circle of radius 10 centimetre under the influence of magnetic field of 0.1 T .
when the particles at a point P a uniform electric field is switched on so that the particle starts moving along the tangent with uniform velocity the electric field is

Q. At what distance from the centre of a uniformly charged ring, maximum value of electric field will be obtained?

1. $3\text{m}$
2. $5\text{m}$
3. $7\text{m}$
4. $9\text{m}$

Q. If in the concentric hollow spheres of radii r and R (where r<R), the charge Q is distributed such that their surface densities are same, then the potential at their common centre is

1. $\frac{Q(r^2+R^2)}{4{\mathrm{\pi \epsilon }}_o(r+R)}$
2. $\frac{Q(r+R)}{4{\mathrm{\pi \epsilon }}_o(r^2+R^2)}$
3. $\frac{QR}{(r+R)}$
4. zero

Q. A point charge $q$ is placed on the line AH and just outside the cube (of side $d$) at a distance of ${}^{\prime }{r}^{\prime }(r<<d)$. Total flux of electric field through the surface ABCD $\left({\varphi }_{ABCD}\right)$ is $-\frac{nq}{8{\epsilon }_0}$. Find the value of n.

Q.

Give two example of scalar quantities.

Q. If a conductor has a potential V≠0 and there are no charges anywhere else outside, then (1)There must be charges on the surface or inside itself (2)here cannot be any charge in the body of the conductor (3)There must be charges only on the surface (4)There must be charges inside the surface