A particle having a mass of 10^$$-$$2 kg carries a charge of 5 $$ \times $$ 10^$$-$$8 C. The particle is given an initial horizontal velocity of 10⁵ m s^$$-$$1 in the presence of electric field $$\overrightarrow E $$ and magnetic field $$\overrightarrow B $$. To keep the particle moving in a horizontal direction, it is necessary that
(1)  $$\overrightarrow B $$ should be perpendicular to the direction of velocity and $$\overrightarrow E $$ should be along the direction of velocity

(2)  Both $$\overrightarrow B $$ and $$\overrightarrow E $$ should be along the direction of velocity

(3)  Both $$\overrightarrow B $$ and $$\overrightarrow E $$ are mutually perpendicular and perpendicular to the direction of velocity.

(4)  $$\overrightarrow B $$ should be along the direction of velocity and $$\overrightarrow E $$ should be perpendicular to the direction of velocity

Which one of the following pairs of statements is possible ?

A current loop consists of two identical semicircular parts each of radius R, one lying in the x-y plane and the other in x-z plane. If the current in the loop is $$i$$. The resultant magnetic field due to the two semicircular parts at their common centre is

A galvanometer has a coil of resistance 100 ohm and gives a full scale deflection for 30 mA current. If it is to work as a voltmeter of 30 volt range, the resistance required to be added will be

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