Magnetism and Matter Test -7

Result

Magnetism and Matter Test -7

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

A toroid wound with 60.0 turns/m of wire carries a current of 5.00 A. The torus is iron, which has a magnetic permeability of μ_m = 5000μ₀ under the given conditions. H and B inside the iron are

A
300A/m,1.88T

B
380A/m,1.98T

C
340A/m,1.88T

D
340A/m,2.88T

Solution

H = nI = 60 × 5 = 300A/m
B = μ_oμ_rH = μ_mH

= 5000 × 300 x 4π × 10⁻⁷

= 1.88 T
Question 2
1 / -0

A cube-shaped permanent magnet is made of a ferromagnetic material with a magnetization M of about 500A/m.The side of cube is 20 cm. Magnetic dipole moment of the magnet is.

A
4Am²

B
3Am²

C
5Am²

D
6Am²

Solution

Magnetic Moment = Magnetization × Volume
Side of cube = 20 cm = 0.2 m
= 500 × 0.2 × 0.2 × 0.2 = 4Am²
Question 3
1 / -0

Permeability of a paramagnetic material is expected to decrease with increasing temperature because

A
electrons go into forbidden gap

B
random thermal motion reduces magnetic moment alignment

C
random thermal motion increases magnetic moment alignment

D
electrons stop moving

Solution

Due to temperature thermal velocity of atoms which are in random directions increases hence the alignment of their magnetic moment decreases.
Question 4
1 / -0

If a magnet is suspended over a container of liquid air, it attracts droplets to its poles. The droplets contain only liquid oxygen and no nitrogen because

A
oxygen is ferrimagnetic whereas nitrogen is diamagnetic

B
oxygen is paramagnetic whereas nitrogen is diamagnetic

C
oxygen is diamagnetic whereas nitrogen is paramagnetic

D
oxygen is ferromagnetic whereas nitrogen is diamagnetic

Solution

Oxygen gets feebly magnetised in the direction of external magnetic field, whereas nitrogen gets feebly magnetised in direction opposite to that of external magnetic field.
Question 5
1 / -0

Which of the following features of atomic structure determine whether an element is diamagnetic or paramagnetic

A
atomic weight

B
number of electrons

C
orbital angular momentum, spin angular momentum

D
principal quantum number

Solution

The magnetic moment of a free atom has three principal sources: the spin with which electrons are endowed; their orbital angular momentum about the nucleus; and the change in the orbital moment induced by an applied magnetic field. The first two effects give paramagnetic contributions to the magnetization, and the third gives a diamagnetic contribution.
Question 6
1 / -0

Correct unit of Bohr magneton is

A
J/T

B
J

C
T/J

D
T
Question 7
1 / -0

Diamagnetic susceptibilities are very nearly temperature independent because

A
temperature does not knock off electrons

B
principal quantum number is large

C
spin is only one way

D
there are no unpaired electrons in the same orbital

Solution

Net magnetic moment of a molecule of dimagnetic substance is zero.
Question 8
1 / -0

A powerful magnet attracts

A
all materials.

B
only ferromagnetic materials and their ores.

C
some materials and repels some other materials.

D
only iron and its ores but does not repel any material.

Solution

There are only three types of materials diamagnetic, paramagnetic and ferromagnetic.
Diamagnetic materials will be repeled feebly.
Paramagnetic materials will be attracted feebly.
Only Ferromagnetic materials gets attracted very strongly. As well as their ores also because they will also be ferromagnetic in nature.
Question 9
1 / -0

Which of the following are best suited to make the core of a transformer?

A
soft iron

B
steel

C
alnico

D
none of these

Solution

The core needs to be magnetized and demagnetized frequently during the working of a transformers.
Soft iron is used as core.
Since it easy to magnetize and demagnetize with less energy loss.
Question 10
1 / -0

The value of Curie temperature for $$Ni$$ is nearly

A
$$631K$$

B
$$770K$$

C
$$890K$$

D
$$1100K$$

Solution

Above $$631 K \ Ni$$ behaves like paramagnetic material.
Question 11
1 / -0

Two magnetic lines of force:

A
never cut each other

B
cut near the poles

C
cut according to the position of the magnet

D
cut at neutral points

Solution

A magnetic field line is that path in space that points in the direction of the magnetic field at every point along it. Walk along a magnetic field line carrying a compass, and the needle will always point in the direction you need to go in order to stay on that magnetic field line (the needle has to be able to pivot up and down as well as around in a circle like most compasses).
If two field lines crossed, then that is resembling that the magnetic field points in two different directions, at one place. There is only one direction to the magnetic field at any place at any time, so this doesn't happen.
Question 12
1 / -0

A freely suspended magnetic needle will always come to rest in which direction ?

A
north-east direction

B
north-west direction

C
north-south direction

D
south-west direction

Solution

Magnetic needle reacts to the magnetic field of earth which is in North-South direction.Hence come to rest in north south direction.
Question 13
1 / -0

Which of the following statements given below is not true in the context of magnetic lines of force ?

A
Magnetic lines of forces are closed continuous curves

B
No two magnetic lines of force can intersect each other

C
Magnetic lines of force are close to each other at the poles

D
They start from the north pole and end on the south pole

Solution

The magnetic lines of force are closed concentric circles and hence, the starting or ending point cannot be specified exactly except the direction. Therefore, the direction of magnetic field lines outside the magnet is from North Pole to South Pole and the direction of magnetic field lines inside the magnet is from south pole to the north pole. Start and end cannot be found.
Question 14
1 / -0

The space around a magnet where its influence can be detected is called ..............

A
curve

B
magnetic field

C
magnetic needle

D
horse shoe

Solution

The space around a magnet where its influence can be detected is called Magnetic field.
A magnetic field is the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude (or strength).
Question 15
1 / -0

Which of the following is/are true for "magnetic lines of force around a bar magnet"?

A
are closed continuous curves

B
travel from north to south outside the magnet

C
bend around the length of magnet

D
all the above

Solution

The properties of magnetic lines are
1. They travel from a north pole to south pole
2. They bend around the length of the magnet
3. They form a closed loop with continuous lines.
Question 16
1 / -0

Magnetic lines of force can pass through:

A
only magnetic substances

B
only non-magnetic substances

C
both (a) and (b)

D
none of the above

Solution

Magnetic field can penetrate through both magnetic and non-magnetic substances.
Question 17
1 / -0

Magnetic lines do not intersect one-another because:

A
they are at a distance

B
they are in the same direction

C
they are parallel to one another

D
in the point of intersection there will be two direction of the magnetic field, which is impossible

Solution

Each point on the magnetic line gives the direction of the magnetic field. If two field lines intersect then there will be two direction of magnetic field at that particular point which is impossible.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Magnetism and Matter Test -7

Result

Magnetism and Matter Test -7

Score

-

Rank

-

SHARING IS CARING

Question 1

300A/m,1.88T

380A/m,1.98T

340A/m,1.88T

340A/m,2.88T

Solution

Question 2

4Am2

3Am2

5Am2

6Am2

Solution

Question 3

electrons go into forbidden gap

random thermal motion reduces magnetic moment alignment

random thermal motion increases magnetic moment alignment

electrons stop moving

Solution

Question 4

oxygen is ferrimagnetic whereas nitrogen is diamagnetic

oxygen is paramagnetic whereas nitrogen is diamagnetic

oxygen is diamagnetic whereas nitrogen is paramagnetic

oxygen is ferromagnetic whereas nitrogen is diamagnetic

Solution

Question 5

atomic weight

number of electrons

orbital angular momentum, spin angular momentum

principal quantum number

Solution

Question 6

J/T

J

T/J

T

Question 7

temperature does not knock off electrons

principal quantum number is large

spin is only one way

there are no unpaired electrons in the same orbital

Solution

Question 8

all materials.

only ferromagnetic materials and their ores.

some materials and repels some other materials.

only iron and its ores but does not repel any material.

Solution

Question 9

soft iron

steel

alnico

none of these

Solution

Question 10

$$631K$$

$$770K$$

$$890K$$

$$1100K$$

Solution

Question 11

never cut each other

cut near the poles

cut according to the position of the magnet

cut at neutral points

Solution

Question 12

north-east direction

north-west direction

north-south direction

south-west direction

Solution

Question 13

4Am²

3Am²

5Am²

6Am²