The ratio of the dimensions of Planck's constant and that of moment of inertia has the dimensions of

  • angular momentum

  • time

  • velocity

  • frequency


D.

frequency

We know that, energy of an emtted particle

               E = hvh = Ev

Planck's constant, h = ML2T-2T-1 = ML2T-1                    ......(i)and Moment of Inertia,I = mr2   I = ML2                                                             ....... (ii)On dividing Eq.(i) by Eq.(ii), we get       hI = ML2T-1ML2 = T-1 = 1Ti.e,  hI = T-1 = frequency of a particle.


A body of the mass 50 kg is suspended using a spring balance inside a lift at rest. If the lift starts falling freely, the reading of the spring balance is

  • < 50 kg

  • = 50 kg

  • > 50 kg

  • = 0


D.

= 0

Given,

Mass of the body, m = 50 kg

When lift is moving down,

Scale reading = m g - ag

If lift starts freely, then

Now, scale reading = m g - gg = 0


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If energy (E), velocity (v) and time (T) are chosen  as the fundamental quantities, the dimensional formula of surface tension will be

  • [Ev-2T-1]

  • [Ev-1T-2]

  • [Ev-2T-2]

  • [Ev-2T-2]


C.

[Ev-2T-2]

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A substance of mass 49.53 g occupies 1.5 cm3 of volume. The density of the substance (in g cm-3) with correct number of significant figures is

  • 3.3

  • 3300

  • 3302

  • 33.0


D.

33.0

Mass of the substances (m) = 49.53 g

Volume (V) = 1.5 cm3

We know that,

d = mVd = 49.531.5d = 33.02d = 33.0


The S.I. unit of specific heat capacity is

  • JK-1

  • J kg-1

  • J mol-1 K-1

  • J kg-1 K-1


D.

J kg-1 K-1

The SI unit of specific heat capacity is J kg-1 K-1.


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