Physics

Distance travelled by linear scale of screw gauge during two full rotation of circular scale is 1mm and circular scale has 50 divisions. In an experiment to measure thickness of a plate, six divisions of main scale are clearly visible and 28th division of circular scale coincides with reference line. Moreover when studs touch each other, zero of circular scale lies 4 division below the reference line, thickness of the plate will be:

A charge q of mass m enters a region of electric field E = -E₀ĵ with a velocity v₀î + v₀ĵ at origin. Find the x coordinate where the charge hits the x axis again. (Neglect effect of gravity)

In free space, two particles of mass m each are initially both at rest at a distance a from each other. They start moving towards each other due to their mutual gravitational attraction. The time after which the distance between them has reduced to a/2 is

Abhishek and Deepak have two samples of magnetic materials X and Y. Experimentally they determine the following properties of the samples.
| | Retentivity | Coercivity |
| :--- | :--- | :--- |
| X | 1.5 T | 20 Am?¹ |
| Y | 1.0 T | 100 Am?¹ |
Considering this, choose best choice

A rod of mass m and length L is hinged at its top end. If the rod is in equilibrium making an angle of 30° with the vertical when a horizontal force F is applied as shown in figure, then the value of F is:

An ideal gas undergoes a cyclic process whose indicator diagram is as shown in the figure. Find the work done by the gas in 1 complete cycle.

A ray of light is reflected by two perpendicular plane mirrors as shown. The angle θ is equal to:

A proton of mass m and charge q enters a region of uniform magnetic field of a magnitude B with a velocity v directed perpendicular to the magnetic field. It moves in a circular path and leaves the magnetic field after completing a quarter of a circle. The time spent by the proton inside the magnetic field is proportional to:

If the intensity of light in double slit experiment from slit 1 and slit 2 are I₀ and 25I₀ respectively, find the ratio of intensities of light at minima and maxima in the interference pattern.

Two trains are approaching each other on the same track with velocity 100 km/h and 50 km/h. When they are at a distance of 300 km from each other, a bird starts flying from train 1 towards train 2. When the bird reaches train 2, it instantly reverses its direction and flies again towards train 1. This process continues till the bird is trapped between the trains when they collide. If the bird always travels at a constant speed 200 km/h, the total distance the bird flies is: