WB JEE 2020

The bob of a swinging second pendulum (one whose time period is 2 s) has a small speed v0 at its lowest point. It height from this lowest point 2.25 s after passing through it, is given by

The frequency v of the radiation emitted by an atom when an electron jumps from one orbit to another is given by v = k\(\delta\)E, where k is a constant and \(\delta\)E is the change in energy level due to the transition. Then, dimension ...

Consider the vectors \(A = \hat i + \hat j - \hat k\)
,\(B = 2\hat i - \hat j + \hat k\) and \(C = {1 \over {\sqrt 5 }}\left( {\hat i - 2\hat j + 2\hat k} \right)\)
. What is the value of C. (A\(\times\) B) ?

The intensity of light emerging from one of the slits in a Young's double slit experiment is found to be 1.5 times the intensity of light emerging from the other slit. What will be the approximate ratio of intensity of an interference maxim...

In a Fraunhofer diffraction experiment, a single slit of width 0.5 mm is illuminated by a monochromatic light of wavelength 600 nm. The diffraction pattern is observed on a screen at a distance of 50 cm from the slit. What will be the linea...

Consider an engine that absorbs 130 cal of heat from a hot reservoir and delivers 30 cal heat to a cold reservoir in each cycle. The engine also consumes 2 J energy in each cycle to overcome friction. If the engine works at 90 cycles per mi...