# Physical Quantities

## Trending Questions

**Q.**Which set of quantities can be taken as a set of fundamental quantities?

- Mass, time and velocity
- Mass, time and volume
- Charge, time and area
- Current, momentum and acceleration.

**Q.**In a system of units if force (F), acceleration (A) and time (T) are taken as fundamental units, then the dimensional formula of energy is:

- FA2T
- FAT2
- FA2T3
- FAT

**Q.**

Why gravitational potential energy is negative?

**Q.**

The SI unit of a physical quantity is pascal-second. The dimensional formula of this quantity will be:

[ML−1T−1]

[M−1L3T0]

[ML2T−1]

[ML−1T−2]

**Q.**

Name the nearest star from the earth and its distance in kilometers.

**Q.**

Give an example of dimensionless quantity with unit.

**Q.**

Plancks constant has the same dimensions as

Angular momentum

Linear momentum

Work

Coefficient of viscosity

**Q.**The moment of inertia of a square plate of side l about the axis passing through one of the corner and perpendicular to the plane of the square plate is given by:

- Ml212
- Ml2
- Ml26
- 23Ml2

**Q.**

What is the symbol of Density?

**Q.**

A cube of metal is subjected to a hydrostatic pressure of $4GPa$. The percentage change in the length of the side of the cube is close to: (Given bulk modulus of metal, $B=8\times {10}^{10}Pa$)

$0.6$

$20$

$1.67$

$5$

**Q.**

What are the meaning of w.r.t in physics and full form?

**Q.**

What is dimensionless quantity? Give examples.

**Q.**

Is impulse a vector or scalar?

**Q.**

Two parallel plates are 0.03m apart. The electric field intensity between them is 3000 newton per coulomb. Calculate the potential difference between the plates?

**Q.**If force, time and velocity are treated as fundamental quantities, then dimensional formula of energy will be

- [FTV]
- [FT2V]
- [FTV2]
- [FT2V2]

**Q.**

The meter is defined as the distance traveled by light in vacuum in 1/299792458 sec. Why it has been chosen not anything else?

**Q.**

Name the factor on which moment of inertia of a body depends

**Q.**

A plane electromagnetic wave, has a frequency of $2.0\times {10}^{10}Hz$ and its energy density is $1.02\times {10}^{\u20138}\raisebox{1ex}{$J$}\!\left/ \!\raisebox{-1ex}{${m}^{3}$}\right.$ in vacuum. The amplitude of the magnetic field of the wave is close

$($$\begin{array}{l}\frac{1}{4\pi {\epsilon}_{0}}=9\times {10}^{9}\frac{N{m}^{2}}{{C}^{2}}\end{array}$and speed of light $=3x{10}^{8}m{s}^{-1})$

$160nT$

$150nT$

$180nT$

$190nT$

**Q.**Van de Graaff generator is used for

- Production of X-ray beam.
- Generating large currents.
- Storing electrical energy
- Generating high potential of the range of few million volts.

**Q.**

Electrical Pressure is also called?

Current

Voltage

Resistance

Power

**Q.**Using the concept of force between two infinitely long parallel current carrying conductors, define one ampere of current.

**Q.**

Aluminum crystallizes in a cubic close-packed structure. Its metallic radius is 125 pm. (i) What is the length of the side of the unit cell? (ii) How many unit cells are there in $1.00{\mathrm{cm}}^{3}$ of aluminum?

**Q.**If Surface tension (S), Moment of Inertia (I) and Planck's constant (h), were to be taken as the fundamental units, then the dimensional formula for linear momentum would be:

- S32 I12 h0
- S12 I12 h0
- S12 I32 h−1
- S12 I12 h−1

**Q.**

Which will exert more pressure, $100kg$ mass on $10{m}^{2}$ or $50kg$ on $4{m}^{2}$ ? Give reason.

**Q.**If photons have no mass, how can they have momentum?

**Q.**The dimension of 1√ϵ0μ0 is that of

- Velocity
- Capacitance
- Distance
- Time

**Q.**Two slits are separated by 0.3 mm. A beam of 500 nm light strikes the slits, producing an interference pattern. The number of maxima observed in the angular range −30∘<θ<30∘.

- 299
- 399
- 499
- 599

**Q.**

Unit of moment of inertia in MKS system is:

$kg\times c{m}^{2}$

$kg/c{m}^{2}$

$kg\times {m}^{2}$

$Joule\times m$

**Q.**

The characteristics of physical quantity is/are

It should be convenient size.

It should be easily replicated.

It should not change with time or place.

All the above

**Q.**

Why is the distance between stars expressed in light years? What do you understand by the statement that a star is eight light-years away from the Earth?