AIEEE 2003 | Magnetic Properties of Matter Question 74 | Physics

A thin rectangular magnet suspended freely has a period of oscillation equal to $$T.$$ Now it is broken into two equal halves (each having half of the original length) and one piece is made to oscillate freely in the same field. If its period of oscillation is $$T',$$ the ratio $${{T'} \over T}$$ is

$${1 \over {2\sqrt 2 }}$$

$${1 \over 2}$$

$$2$$

$${1 \over 4}$$

AIEEE 2003

MCQ (Single Correct Answer)

-1

A magnetic needle lying parallel to a magnetic field requires $$W$$ units of work to turn it through $${60^ \circ }.$$ The torque needed to maintain the needle in this position will be :

$$\sqrt 3 \,W$$

$$W$$

$${{\sqrt 3 } \over 2}W$$

$$2W$$

AIEEE 2003

MCQ (Single Correct Answer)

-1

The magnetic lines of force inside a bar magnet

are from north-pole to south-pole of the magnet

do not exist

depend upon the area of cross-section of the bar magnet

are from south-pole to north-pole of the Magnet