The angle of dip at a place, when horizontal and vertical components of earth's field are equal is ______________.

(a)

45°

(b)

60°

(c)

30°

(d)

0°

When current is doubled deflection is also doubled in ______________.

(a)

moving coil galvanometer

(b)

tangent galvanometer

(c)

both of them

(d)

neither of two

A long straight conductor carrying a current lies along the axis of a ring. The conductor will exert a force on the ring if _______________.

(a)

carries a current

(b)

has uniformly distributed charge

(c)

has non-uniformly distributed

(d)

none of the above

The direction of the magnetic force on a positive charge moving in a magnetic field is given by ________________.

(a)

thumb rule

(b)

left hand rule

(c)

right hand rule

(d)

cork screw rule

Consider the motion of a charged particle in a uniform magnetic field directed into the paper. If velocity v of the particle is in the plane of the paper, the charged particle will describe a _____________.

(a)

straight line

(b)

circle

(c)

ellipse

(d)

hyperbola