Para-, dia- and ferromagnetic substances; effect of temperature — practice questions

Question 1 · difficulty L1 · recall

A diamagnetic substance has magnetic susceptibility that is typically

• A. small and negative
• B. large and positive
• C. exactly one
• D. infinite and negative

Question 2 · difficulty L1 · understanding

A paramagnetic substance has magnetic susceptibility that is typically

• A. small and negative
• B. small and positive
• C. zero at every temperature
• D. very large and negative

Question 3 · difficulty L2 · understanding

Ferromagnetic materials are distinguished by

• A. a strictly zero magnetic response
• B. only weak negative susceptibility
• C. very strong magnetization and domain alignment
• D. absence of atomic magnetic moments

Question 4 · difficulty L2 · application

Which material is weakly repelled from a region of stronger magnetic field?

• A. A paramagnetic material
• B. A ferromagnetic material below Curie temperature
• C. An ideal soft iron sample
• D. A diamagnetic material

Question 5 · difficulty L2 · understanding

A solenoid has a core made of material with relative permeability 400 . The magnetic field produced in the interior of solenoid is 1.0 T . The magnetic intensity in SI units is $\alpha \times 10^5$. The value of $\alpha$ is $\_\_\_\_$ . (Free space permeability $\mu_0=4 \pi \times 10^{-7}$ SI units.)

• A. $\frac{25}{\pi}$
• B. $\frac{1}{16 \pi}$
• C. $\frac{1}{\pi}$
• D. $\frac{1}{4 \pi}$

Question 6 · difficulty L2 · understanding

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Consider a ferromagnetic material : Assertion (A) : The individual atoms in a ferromagnetic material possess a magnetic dipole moment and interact with one another in such a way that they spontaneously align themselves forming domains. Reason (R) : At high enough temperature, the domain structure of ferromagnetic material disintegrates. Thus, magnetization will disappear at high enough temperature known as Curie temperature. In the light of the above statements, choose the correct answer from the options given below :

• A. (A) is true but (R) is false
• B. Both (A) and (R) are true and (R) is the correct explanation of (A)
• C. (A) is false but (R) is true
• D. Both (A) and (R) are true but (R) is not the correct explanation of (A)

Question 7 · difficulty L2 · understanding

The percentage increase in magnetic field (B) when space within a current carrying solenoid is filled with magnesium (magnetic susceptibility $\chi_{\mathrm{Mg}}=1.2 \times 10^{-5}$ ) is :

• A. $\frac{5}{3} \times 10^{-5} \%$
• B. $\frac{5}{6} \times 10^{-4} \%$
• C. $\frac{5}{6} \times 10^{-5} \%$
• D. $\frac{6}{5} \times 10^{-3} \%$

Question 8 · difficulty L2 · understanding

The relationship between the magnetic susceptibility $(x)$ and the magnetic permeability $(\mu)$ is given by : ( $\mu_0$ is the permeability of free space and $\mu_T$ is relative permeability)

• A. $X=\frac{\mu}{\mu_0}-1$
• B. $X=\frac{\mu_{\mathrm{r}}}{\mu_0}+1$
• C. $\chi=\mu_r+1$
• D. $X=1-\frac{\mu}{\mu_0}$

Question 9 · difficulty L2 · understanding

Match List - I with List - II. List - I List - II (A) Magnetic induction (I) Ampere meter 2 (B) Magnetic intensity (II) Weber (C) Magnetic flux (III) Gauss (D) Magnetic moment (IV) Ampere meter Choose the correct answer from the options given below:

• A. (A)-(III), (B)-(IV), (C)-(II), (D)-(I)
• B. (A)-(III), (B)-(II), (C)-(I), (D)-(IV)
• C. (A)-(III), (B)-(IV), (C)-(I), (D)-(II)
• D. (A)-(I), (B)-(II), (C)-(III), (D)-(IV)

Question 10 · difficulty L2 · understanding

Paramagnetic substances: A. align themselves along the directions of external magnetic field. B. attract strongly towards external magnetic field. C. has susceptibility little more than zero. D. move from a region of strong magnetic field to weak magnetic field. Choose the most appropriate answer from the options given below:

• A. A, B, C Only
• B. A, C Only
• C. A, B, C, D
• D. B, D Only