Electric Charge...

Force between two charges $$q_1$$ and $$q_2$$ separated by a distance r is proportional to $$q _ { 1 } q _ { 2 } / r ^ { 2 }$$ . Proportionality constant is 

Eight point charges (can be assumed as small spheres uniformly charged and their centres at the corner of the cube) having values q each are fixed at vertices of a cube. The electric flux through square surface ABCD of the cube is 

A charge +Q is located in space at point $$(x=1 m,y=10m, z=5m)$$. What is the total electric flux that passes through the $$y-z$$ plane?

A light beam travelling in the x-direction is described by the electric field $${ E }_{ y }=(300V{ m }^{ -1 })sin\quad \omega (t-x/c).$$ An electron is constrained to move along the y-direction with a speed of $$2.0\times  {10}^7 { m }^{ -1 }$$ Find the maximum electric force and the maximum magnetic force on the electron

Choose the correct answer (Only one option is correct) from the following.

Statement-1: A deuteron and $$\alpha  - particle$$ are placed in an electric field. If $${F_1}\;{\text{and}}\;{F_2}$$ be the forces acting on them and $${a_1}\;{\text{and}}\;{a_2}$$ be their accelerations respectively, then $${a_1} = {a_2}.$$.

Statement-2: Forces will be same in the electric field.

Flux through the rectangular piece of area 10 cm by 20 cm when placed ( as shown in an uniform electric field of 200 N/C, ) is 

Two parallel plates have charges $$Q_1$$ and $$Q_2$$ on them and the capacitance is c. The potential difference between them is

As shown in figure a dust particle with mass $$m=5.0\times 10^{-9}$$ kg and charge $$q_{0}=2.0 nC$$ starts from rest at point a and moves in a straight line to point b. What is its speed v at point b?

Four charges $$+Q,-Q,+Q$$ and $$-Q$$ are situated at the corners of a square; in a sequence then at the centre of the square:

There are two charges $$+2\mu\ C\ and -3\mu\ C$$. The ratio of forces acting on them will be