Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

Multiple choice physics dynamics - explaining motion air resistance fluid friction moving through fluids

State whether the given statement is true or false:

Fluid friction is more than solid friction.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Static friction is the force that is the greatest. This is because it opposes motion the strongest between the various types of friction. Friction is greatest in the absent of lubrication,and since there is presence of fluid lubricant in fluid friction it has less friction as compared to solid friction,and in solid friction there is no presence of any lubricant.Hence the given statement is false.

Multiple choice physics dynamics - explaining motion air resistance fluid friction moving through fluids

A man of mass $m$ walks from end $A$ to the other end $B$ of a boat of mass $M$ and length $l$. The coefficient of friction between the man and the boat is $ \mu $ and neglect any resistive force between the boat and the water.

  1. If the man runs at his maximum acceleration, the acceleration of the boat is $ (m/M)g $.

  2. The maximum time take by the men to reach the other end of the boat is $ \sqrt { \dfrac { 2Ml }{ (M+m)\mu g } } $.

  3. If the man runs at his maximum acceleration, the acceleration of the boat is $ \dfrac { m }{ m+M } \mu g $.

  4. The minimum time take by the men to reach the other end of the boat is $ \sqrt { \dfrac { 2ml }{ (M+m)\mu g } } $.
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation

The motion of the man and the boat involves Newton's laws and friction. The acceleration of the boat is derived from the force balance, and the time taken is derived from the kinematic equations under constant acceleration.

Multiple choice physics magnetism and matter paramagnetic material classification of magnetic material magnetism

Out of given paramagnetic substance (Calcium, Chromium, Oxygen and Tungsten) which substance has maximum susceptibility?

  1. Calcium

  2. Chromium

  3. Oxygen

  4. Tungsten
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Susceptibility at the standard temperature, $T=300K$

Calcium $\rightarrow 1.9\times 10^{-5}$ 
Chromium $\rightarrow 2.7\times 10^{-4}$
 Oxygen $\rightarrow 2.1\times 10^{-6}$
Tungsten $\rightarrow 6.8\times 10^{-5}$
Chromium have maximum susceptibility.
The correct option is B.

Multiple choice physics magnetism and matter paramagnetic material classification of magnetic material magnetism

A paramagnetic liquid is taken in a U-tube and arranged so that one of its limbs is kept between pole pieces of the magnet. The liquid level in the limb is

  1. goes down

  2. rises up

  3. remains same

  4. first goes down and then rise
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When a paramagnetic liquid is taken in U-tube and one arm is placed between the poles of strong magnet, the liquid is feebly attracted by the magnet. Therefore, the level of the solution in the arm rises.

Multiple choice physics magnetism and matter paramagnetic material classification of magnetic material magnetism

The magnetic susceptibility of a paramagnetic material at $-73^0$ is $0.0075$, its value at $-173^0$C will be

  1. $0.0045$

  2. $0.0030$

  3. $0.015$

  4. $0.0075$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Given,
$X=0.0075 \,\,at\,\,\, T=-73^{\circ}$
Curie's law, $X=\cfrac{C}{T}$
$X _{1} \propto \cfrac{1}{T _{1}}$
$\therefore \cfrac{X _{1}}{X _{2}}=\cfrac{T _{2}}{T _{1}}$
$X _{2}=X _{1}\times \cfrac{T _{1}}{T _{2}}=0.0075\times \cfrac{273-73}{2.73-173}=0.015$

Multiple choice physics magnetism and matter paramagnetic material classification of magnetic material magnetism

Assertion : Paramagnetic substances get weakly attracted to a magnet.
Reason : They have tendency to move from a region of strong magnetic field to weak magnetic field

  1. If both assertion and reason are true and reason is the correct explanation of assertion.

  2. If both assertion and reason are true and reason is not the correct explanation of assertion.

  3. If assertion is true but reason is false.

  4. If both assertion and reason are false
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Paramagnetic substances have tendency to move from a region of weak magnetic field to strong magnetic field i.e., they get weakly attracted to a magnet.

Multiple choice physics magnetism and matter paramagnetic material classification of magnetic material magnetism

Consider the following statements I and II.
(I) Paramagnetism is explained by domain theory 
(II) Susceptibility of a diamagnetic substance is independent of temperature.
Identify the correct choice from the following. 

  1. Both I and II are correct

  2. Both I and II are incorrect

  3. I is correct and II is incorrect.

  4. I is incorrect and II is correct
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Paramagnetism is explained by the alignment of atomic magnetic moments, not domain theory, which applies to ferromagnetism. The magnetic susceptibility of diamagnetic substances is indeed independent of temperature.

Multiple choice physics magnetism and matter paramagnetic material classification of magnetic material magnetism

Assertion(A) : Earth's magnetic field inside a closed iron box is less as compared to the outside.
Reason(R) : The magnetic permeability of iron is low.

  1. Both A, R are true and R is the correct explanation of A

  2. Both A, R are true and R is not correct explanation of A

  3. A is true R is false

  4. A is false R is true
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The Earth's magnetic field inside a closed iron box is reduced due to magnetic shielding, which occurs because iron has high magnetic permeability, not low. Therefore, the assertion is true but the reason is false.

Multiple choice physics magnetism and matter paramagnetic material classification of magnetic material magnetism

The meniscus of a liquid contained in one of the limbs of a narrow U-tube is held electromagnet with the meniscus in line with the field. The liquid is seen to rise. This indicates that the liquid is

  1. anti-ferromagnetic

  2. paramagnetic

  3. diamagnetic

  4. non-magnetic
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Paramagnetic liquid tends to flow from region of weaker magnetic fields to stronger magnetic fields..