Experimental investigations show that the intensity of solar radiation is maximum for a wavelength 480 nm in the visible region. Estimate the surface temperature of sun. (Given Wien's constant b = 2.88 x 10-3 mK.)
4000 K
6000 K
8000 K
106 K
The temperature of an ideal gas is increased from 120 K to 480 K. If at 120 K, the root mean square speed of gas molecules is v, then at 480 K, it will be
4v
2v
n identical droplets are charged to V volt each. if they coalesce to form a single drop, then its potential will be
n2/3V
n1/3V
nV
V/n
A.
n2/3V
Let the radius of each droplet be r units. So, the volume of each droplet is equal to .
Thus, n droplets have the total volume equal to .
Since, the number of the drop would be equal to the total volume of the droplets hence,
⇒ R3 = nr3
⇒ R = n1/3r .... (i)
The capacitance of each droplet is equal to,
and thus the charge of each droplet would be equal to
.... (ii)
The capacitance of the bigger drop would be equal to
The potential of the bigger drop would be equal to V (say).
Hence,
A particle of mass m is attached to three identical massless springs of spring constant k as shown in the figure. The time period of vertical oscillation of the particle is
A spring of force constant k is cut into three equal parts. The force constant of each part would be
3k
k
2k
A body floats in water with 40% of its volume outside water. When the same body floats in oil, 60% of its volume remains outside oil. The relative density of the oil is
0.9
1.2
1.5
1.8
A uniform long tube is bent into a circle of radius R and it lies in vertical plane. Two liquids of same volume but densities ρ and δ fill half the tube. The angle θ is
Two solid spheres of same metal but of mass M and 8M fall simultaneously on a viscous liquid and their terminal velocities are v and nv, then value of n is
16
8
4
2
A particle is executing linear simple harmonic motion of amplitude A. At what displacement is the energy of the particle half potential and half kinetic ?
The equation of a progressive wave is where x is in metre and t is in second. The velocity of the wave is