Choose the correct alternative :- The formula -GMm`(1//r_2 1//r_1)` is `more//less` accurate than the formula `mq(r_2- r_1)` for the difference of potential energy between two points `r_2 and r_1`, distance away from the centre of the earth.

In the circit show in the figure E_1 = 3V, E_2 = 2V, E_3 = 1V and the resistances R = r_1 = r_2 = r_3 = 1Omega . Find the potential difference between the points A and B and the current through each branch.

An object of mass m is raised from the surface of the earth to a heigt equal to the radius of the earth , that is, taken from a distance R to 2R from the centre of the earth. What is the gain in its potential energy?

Write the vector form of force acting between two charges q_1 and q_2 having vec r_1 and vec r_2 as their position vectors respectively.

A spherical conduting shell of inner radius r_1 and outer radius r_2 has a charge Q. A charge q is placed at the centre of the shell. Write the expression for the electric field at a point x > r_2 from the centre of the spherical shell.

Two sources of equal emf are connected to an external resistance R. The internal resistance of the two sources are R_1 and R_2(R_1gtR_1) . if the potential difference across the source having internal resistance R_2 is zero, then find vlaue of R.

A sphere S_1 of radius r_1 encloses a charge Q. If there is another concentric sphere S_2 of the radius r_2(r_2>r_1) and there be no additional charges between S_1 and S_2 find the ratio of electric flux through S_1 and S_2

Consider two conducting spheres of radii of R_1 and R_2 with R_1 > R_2 . If the two are at the same potential the larger sphere has more charge than the smaller spheres. State whether the charge density of the smaller sphere is more or less than that of the larger one.

Two resistance r_1 and r_2 (r1< r2) are joined in parallel. The equialent resistane R is such that

If in a triangle (1-(r_1)/(r_2))(1-(r_1)/(r_3))=2 then the triangle is right angled (b) isosceles equilateral (d) none of these

Two cells of e.m.f E_1 and E_2 have internal resistance r_1 and r_2 respectively. What is the corresponding formula for the series combination?