Tag: physical quantities like mass and weight

Questions Related to physical quantities like mass and weight

Metre is the SI unit of

  1. mass

  2. volume

  3. length

  4. area


Correct Option: C
Explanation:

Metre is the SI unit of length.

Pressure is a standard unit of time.

  1. True

  2. False


Correct Option: B
Explanation:

Second is a standard unit of time. Thus the given statement is false.

Quantity of matter contained in a body is ....................... .

  1. Mass

  2. density

  3. relative density

  4. Volume


Correct Option: A
Explanation:

Mass of the body is defined as the quantity of matter contained in a body.

Knot is a measure of:

  1. The speed of ship

  2. The curvature of spherical objects

  3. Solar radiation

  4. Intensity of earthquake shock.


Correct Option: A
Explanation:

Knot is a measure of the speed of ship. The term knot dates from the 17th century, when sailors measured the speed of their ship by using a device called a "common log".

Hence, option A is correct.

Which one of the following does not have unit of force per unit area:

  1. $Stress$

  2. $Strain$

  3. $Youngs Modulus$

  4. $pressure$


Correct Option: B
Explanation:
  • Stress  is the force per unit area on a body that tries to cause a change in shape. It is measured by the SI unit is Pascal.

  • Strain is defined as the deformation produced in a solid due to stress. It is measured by calculating the ratio of the two lengths. As a result it does not have any unit.  

  • Force is measured by the product of mass and acceleration. Its SI unit is Newton.

  • Pressure is measured by force per unit area. Its SI unit is Pascal.

So correct answer is option (B).

The base quantity among the following is:

  1. Speed

  2. Weight

  3. Length

  4. Area


Correct Option: C
Explanation:

 A base quantity is one of a conventionally chosen subset of physical quantities, where no quantity in the subset can be expressed in terms of the others. There are seven basic fundamental quantities: Length, mass, time, electric current, amount of substance, luminous intensity and temperature. So, the base quantity among the following is length.

If $L = \left( {20 \pm 0.01} \right)m$ and $B = \left( {10 \pm 0.02} \right)m$ then $\dfrac{L}{B}$ is 

  1. $ \left( {2 \pm 0.03} \right)m$

  2. $ \left( {2 \pm 0.015} \right)m$

  3. $ \left( {2 \pm 0.01} \right)m$

  4. $ \left( {2 \pm 0.005} \right)m$


Correct Option: A
Explanation:

$l=20\pm 0.01, B=10\pm 0.02$

Take $l=20+0.01, B=10+0.02$
Then $\cfrac {l}{B}=\cfrac {20.01}{10.02}=1.997$
Taken $l= 20-0.01$, $B=10-0.02$
There $\cfrac {l}{B}=\cfrac {19.99}{9.98}=2.003$
$\therefore$ The answer is $(2\pm 0.003)m$ .

Gauss is the unit of -

  1. B

  2. H

  3. M

  4. I


Correct Option: A
Explanation:

The Gauss (G), is the cgs unit of measurement of magnetic flux density (B). One gauss is defined as one maxwell per square centimeter.

Debye is a unit of

  1. rms velocity

  2. force

  3. specific gravity

  4. electric dipole moment


Correct Option: D
Explanation:

The debye (symbol: D) is a CGS unit of electric dipole moment, named in the honour of the physicist Peter J. W. Debye.
It is defined as $ 1\times { 10 }^{ -18 }$ statcoulomb-centimetre.