Question

1. Which of the following statements are correct? The force lines of the electric field a) cannot cross each other at right angle; b) cannot originate from a negative charge; c) cannot be closed; d) cannot cross equipotential surfaces at right angle; e) cannot be parallel to each other. 2. A positive charge g is located in the center of the conducting spherical layer shown in the figure. What is the absolute value of the strength of electrical field in different regions around the charge? c) b) rR 4ner R;<r<R PR2 3. A charge q is located at the distance from the infinitely long thread with the linear charge density . What is the force of the interaction between them? a) qu(tres); b) qu(2780); c) M(4tres); d)q(6tro); e)q(8nrto); 4. The potential of the electric field depends only on x coordinate aso-ax+bx, where a wb are constants. What is the distribution of the volume charge density p(x)? a) p(x) - alox®/12 + bx; b) p(x)- 2a8ox?; c) p(x) -12ax?; d) p(x) = 12a.x; e) p(x) - 1280x 5. The potential energy of the system of three point charges shown in the figure is equal to: a) -q/(4te); b) 3q/(4RE 1); c)-3q/(48); d)q/(4x801); e) 29'/(4181); 6. A conducting ball is charged with the surface charge density o. The ball potential is. - 1 -4 What is its radius? a) 8.p/4ro; b) Ep/2n0; c) Ep/8no; d) 26/to; e) ep/o; 0. 7. A dipole placed in the electric field as is shown in the figure will a) turn clockwise and move to the right; b) turn clockwise and move to the left; c) turn counterclockwise and move to the right; d) turn counterclockwise and move to the left; e) turn counterclockwise and stay at the same position. Ho 8. What is the strength of the electric field if the potential of the field depends on the coordinates x,y,z as Par-y-=), where a is constant? a) -2a[(xi+yj+zk)); b)-2a[(-xityj+zk)); c)-2a[(xi-yj+zk)]; d)-20[(xi+yj-zk)] : e) -20[(xi-yj-zk)].

plz answer with some notes like explation .

Answer 1

Pa Incorrect :- As electric lines of force can never cross each other what ever be its angle of intersection . (6) correct :- As force lines originates from a tre change. (c) Incorrect :- Little surprising but yes, it w true 1. for an induced field. d Incorrect :- 't always cross equipotential surface I normally else there will be some workclone (e) Incorrect it can be parallel. enample - Inside a capacitor. 0 for rar, Using gauss law. Exhar2 = 9 => E= 9 For R<r< Re the same result E= V for ry R2 also the same result E= LUT Tora wur2 WTEO Y2 EL- ID motortarter charge enclosed = XL

. By using gauss law:- EX QATL = rebut MEDVEO And we know force = charge x Electrie field. so force = es torneo corsi we have potential o = -anttbr According to poisson's equation sans = d so SCW) - C- and tbu) a m (-4923 +b) -12a42 (so option e). Co an sw. -12aton?