WBJEE 2015 (Physics – Category 1) Model Test

In hydrogen spectrum, the longest wavelength in the U-U series is 122×10-9 meter. This corresponds to a transition of electron from the level

The electrostatic potential energy between proton and electron separated by 1A is

The quantities ε₀ and μ₀ denote the free-space permitivity and free-space permeability respectively. If E and B respectively denote the electric and magnetic fields, then which of the following has the dimension of velocity?

Two soap bubbles have radii in the ratio 2:1. What is the ratio of the excess pressure inside them?

At given instant of time, two radioactive elements P and Q have the same number of atoms. It is also known that the mean-life time of P is the same as the half-life time of Q . Then which of the following is correct ?

A non-conducting solid sphere of radius R is uniformly charged. At a distance r from the centre of the sphere the electric field (magnitude) due to the spherical charge distribution

A car moving at a speed of 20 km/hr stops by applying brakes after travelling 5m. If the same car is moving at 40 km/hr, the stopping distance after applying brakes will be

The second overtone of an open pipe is in resonance with the first overtone of a closed pipe of length 2m. Length of the open pipe is

An object is moving away from a vertical concave mirror of focal length 25 m. When the distance of the object is 100 m, the velocity of the object is 5 m/s and it accelerates at the rate of 2 m/s². The distance of the object from the image after 5 sec is

If E = energy, G = gravitational constant, I = impulse and M = mass,the dimension of (GIM²)/E² are same as that of