Acharged particle enters a uniform magnetic field perpendicular to its initial direction travelling in air. The path of the particle is seen to follow the path in figure. Which of statements $1-3$ is/are correct?

$[1]$ The magnetic field strength may have been increased while the particle was travelling in air

$[2]$ The particle lost energy by ionising the air

$[3]$ The particle lost charge by ionising the air

Consider the circular loop having current $i$ and with central point $O$. The magnetic field at the central point $O$ is

An $\alpha$ particle is moving along a circle of radius $R$ with a constant angular velocity $\omega $. Point $A$ lies in the same plane at a distance $2R$ from the centre. Point $A$ records magnetic field produced by $\alpha$ particle. If the minimum time interval between two successive times at which $A$ records zero magnetic field is $‘t’,$ find the angular speed $\omega $, in terms of $t.$

A steady current is set up in a cubic network composed of wires of equal resistance and length $d$ as shown in figure. What is the magnetic field at the centre P due to the cubic network

A coil of one turn is made of a wire of certain length and then from the same length a coil of two turns is made. If the same current is passed in both the cases, then the ratio of the magnetic inductions at their centres will be

Two similar coils of radius $R$ are lying concentrically with their planes at right angles to each other. The currents flowing in them are $I$ and $2I$, respectively. The resultant magnetic field induction at the centre will be