Physical Quantities

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

1. Mass, time and velocity
2. Mass, time and volume
3. Charge, time and area
4. Current, momentum and acceleration.

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

1. $F{A}^{2}T$
2. $FA{T}^2$
3. $F{A}^2{T}^3$
4. $FAT$

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:

1. $\left[M{L}^{-1}{T}^{-1}\right]$

2. $\left[M^{-1}{L}^3{T}^0\right]$

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3. $\left[M{L}^2{T}^{-1}\right]$

4. $\left[M{L}^{-1}{T}^{-2}\right]$

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

1. Angular momentum

2. Linear momentum

3. Work

4. 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:

1. $\frac{M{l}^2}{12}$
2. $M{l}^2$
3. $\frac{M{l}^2}{6}$
4. $\frac{2}{3}M{l}^2$

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, $B=8\times {10}^{10}Pa$)

1. $0.6$

2. $20$

3. $1.67$

4. $5$

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

1. $\left[FTV\right]$
2. $\left[F{T}^{2}V\right]$
3. $\left[FT{V}^2\right]$
4. $\left[F{T}^2{V}^2\right]$

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 $1.02\times {10}^{–8}\raisebox{1ex}{$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 $=3x{10}^{8}m{s}^{-1})$

1. $160nT$

2. $150nT$

3. $180nT$

4. $190nT$

Q. Van de Graaff generator is used for

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

Q.

Electrical Pressure is also called?

1. Current

2. Voltage

3. Resistance

4. 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 $\left(S\right)$, Moment of Inertia $\left(I\right)$ and Planck's constant $\left(h\right)$, were to be taken as the fundamental units, then the dimensional formula for linear momentum would be:

1. $S^{\frac{3}{2}}{I}^{\frac{1}{2}}{h}^0$
2. $S^{\frac{1}{2}}{I}^{\frac{1}{2}}{h}^0$
3. $S^{\frac{1}{2}}{I}^{\frac{3}{2}}{h}^{-1}$
4. $S^{\frac{1}{2}}{I}^{\frac{1}{2}}{h}^{-1}$

Q.

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

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

Q. The dimension of $\frac{1}{\sqrt{{ϵ}_0{\mu }_0}}$ is that of

1. Velocity
2. Capacitance
3. Distance
4. Time

Q. Two slits are separated by $0.3\text{mm}$. A beam of $500\text{nm}$ light strikes the slits, producing an interference pattern. The number of maxima observed in the angular range $-{30}^{\circ }<\theta <{30}^{\circ }$.

1. $299$
2. $399$
3. $499$
4. $599$

Q.

Unit of moment of inertia in MKS system is:

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

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

3. $kg\times m^2$

4. $Joule\times m$

Q.

The characteristics of physical quantity is/are

1. It should be convenient size.

2. It should be easily replicated.

3. It should not change with time or place.

4. 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?