Question

i. Which of the following correctly describes the magnetic field near a long straight wire?

a) The field consists of straight lines perpendicular to the wire.

b) The field consists of straight lines parallel to the wire.

c) The field consists of radial lines originating from the wire.

d) The field consists of concentric circles centred on the wire.


ii. The direction of a magnetic field developed around a current-carrying straight wire can be easily

found by the use of:

a) Right-hand thumb rule

b) Left-hand thumb rule

c) Fleming’s left hand rule

d) Fleming’s right-hand rule


iii. Deduce from the graph that at what distance from the wire, magnetic field strength is minimum?

a) 10 mm

b) 20 mm

c) 40 mm

d) 50 mmv.

iv) The magnetic field at a distance r from a long wire carrying current I is 0.4 Tesla. The value of

magnetic field at a distance 2r is:

a) 0.2 T

b) 0.1 T

c) 0.15 T

d) 1 T​

Answer 1

Answer:

(I ) c .

(ii) c.

(iii) a.

(IV) b.