Magnetism & Matter
Class 12 Physics Chapter 5 Objective in English : Here you can find class 12th physics Objective questions for board exam 2024. Magnetism & Matter objective questions is very important for board exam 2023 – 2024. mcq questions for class 12 physics chapter 5 in English. important question website
12th Physics Chapter 5 Objective Questions in English
- The permeability (μ) of a ferromagnetic substance is : (B.S.E.B. , 2012)
(a) μ > 1
(b) μ = 0
(c) μ < 1
(d) μ = 0
- Nickel is :
(a) Diamagnetic
(b) Paramagnetic
(c) Ferromagnetic
(d) None of these
- Unit of pole strength is :
(a) N
(b) N/Am
(c) Am
(d) T
- The magnetic moment of a steel rod of length ‘l’ is M . It is bent into a semi-circle . The new magnetic moment is :
(a) M
(b) 2Ml
(c) M/l
(d) 2M/π
- A circular current loop is of magnetic moment M. if the radius of the current loop is halved the dipole moment will be :
(a) M
(b) M/2
(c) M/4
(d) 4M
- A short bar magnet is placed with its south pole towards geographical north . The neutral points are situated at a distance of 20 cm from the centre of the magnet . If BH= 0.3 10-4Wb/m2, then the magnetic moment of the magnet is :
(a) 9 Am2
(b) 0.9 Am2
(c) 1.2 Am2
(d) 12 Am2
- The angle between magnetic meridian and geographical meridian is called :
(a) Angle of dip
(b) declination
(c) Angle of polarization
(d) Critical angle
- If the relative permeability of a matter is 0.9999 , then its nature is :
(a) Paramagnetic
(b) Diamagnetic
(c) Ferromagnetic
(d) Non-magnetic
- The angle of dip at magnetic poles is :
(a) 45°
(b) 30°
(c) 0°
(d) 90°
- The unit of magnetic dipole moment is :
(a) n/ampere metre
(b) A/m2
(c) Am2
(d) Wb/m2
- The value of magnetic susceptibility is small but positive in case of :
(a) Paramagnetic substance
(b) Ferromagnetic substances
(c) diamagnetic substances
(d) All substances
- The angle of dip at a place is 30. If the horizontal component of earth’s magnetic field be H, then the field intensity will be :
(a) H/2
(b) 2H/√3
(c) H√2
(d) H√3
- Magnetic permeability of paramagnetic substances is :
(a) 0
(b) > 1
(c) < 1
(d) 1
- A conducting wire of length l metre is bent into a circular loop and I amp current is passed in it . The magnetic moment of the loop will be :
(a) Il2/4π
(b) Il2/2π
(c) πIl2
(d) Il
- Relative permeability of ferromagnetic substances is :
(a) < 1
(b) 1
(c) > 1
(d) >> 1
- Horizontal component of earth’s magnetic field is zero at :
(a) Magnetic poles
(b) Geographical poles
(c) Each place
(d) Magnetic equator
- The coercivity of a small bar magnet is 4×103A/m . If it is inserted inside a solenoid of 500 turns and length 1 m to demagnetize it . The amount of current to be passed through the solenoid will be :
(a) 2.5 A
(b) 5 A
(c) 8 A
(d) 10 A
- S.I. unit of magnetic moment is :
(a) IT-2
(b) Am-2
(c) IT
(d) Am-1
- When the intensity of magnetic field is increased four times the time period of suspended magnetic needle becomes :
(a) Double
(b) half
(c) Four terms