The moment of inertia of a thin rod about an axis passing through its mid point and perpendicular to the rod is $$2400 \mathrm{~g} \mathrm{~cm}^2$$. The length of the $$400 \mathrm{~g}$$ rod is nearly:
A particle moving with uniform speed in a circular path maintains:
If $$c$$ is the velocity of light in free space, the correct statements about photon among the following are:
A. The energy of a photon is $$E=h v$$.
B. The velocity of a photon is $$c$$.
C. The momentum of a photon, $$p=\frac{h v}{c}$$.
D. In a photon-electron collision, both total energy and total momentum are conserved.
E. Photon possesses positive charge.
Choose the correct answer from the options given below:
At any instant of time $$t$$, the displacement of any particle is given by $$2 t-1$$ ($$\mathrm{SI}$$ unit) under the influence of force of $$5 \mathrm{~N}$$. The value of instantaneous power is (in $$\mathrm{SI}$$ unit):