Physics

In a young's double slit experiment with monochromatic light, fringes are obtained on a screen placed at some distance from the slits. If the screen is moved 8 cm towards the slits, the change in fringe width is 4 * 10^-5 m. If the separation between the slits is 1 mm, find the wavelength of light used (in nm ).

12gm of gas occupy a volume of 4 * 10^-3 m³ at a temperature of 7°C. After the gas is heated at constant pressure its density becomes 6 * 10^-4gm/cm³. What is the temperature to which the gas was heated (in kelvin)?

A fish moving up in water (μ = 4/3) with a speed of 4 cm/s observes a bird coming directly towards itself with a speed of 12 cm/s. Find the actual speed of the bird with respect to a stationary observer on the ground.

A hollow sphere (mass m, radius R) is put inside a hollow cone (mass m, radius 3R and semi-angle $30°$ ) as shown in the figure. The whole arrangement is rigidly fixed to the ground at the apex of the cone. Both the sphere and the cone are made of the same material (a = 10^-4/ $°C$ ). Considering that major changes in dimensions could happen only due to heating effects, find the increase in potential energy (in Joule) of the system if it's temperature is increased by   $100°C.$

An electromagnetic wave is represented by the electric field
E⃗ = E₀n̂[ωt + (y − z)]
The direction of propagation of the wave, ŝ is:

A monochromatic light of wavelength 6500 Å is used in YDSE. Now both slits are covered by two thin slab of refractive index 3.2 and 2.7 respectively. By doing so central bright fringe shifts to original 7^th bright fringe. If both slabs have same thickness then thickness of slab is $\left(in\mu m\right).$  

The rest mass of the deuteron, proton and neutron is equivalent to energy of 1877MeV, 939MeV, 940MeV respectively. A deuteron may disintegrate to a proton and neutron if it.

As a train moving with constant speed crosses the platform, the apparent frequency heard by a person standing on the platform during approach and recession differ by 2% of the actual frequency of the horn. If the speed of sound is 330 m/s, find the approximate speed of the train.

A cylindrical metal rod BC of length 1 m and radius 1 cm is joint in series to another rod AB of same material and length but having twice the radius as shown in the figure.

End A is placed at a temperature of 100°C and end C is placed at 50°C temperature. Find the temperature of the junction B.

Two particles start moving from the same point in two different directions. The first particle moves along the positive x-axis with a constant acceleration of 3 m/s². The second particle moves in a straight line making an angle of 60° with the positive x-axis with a constant speed of 24 m/s. Find the time after which the relative velocity of the particles is minimum.