Soil erosion can be prevented by

Which of the following is a method of plant tissue culture?

If the $B-H$ curves of two samples of $P$ and $Q$ of iron are as shown below, then which one of the following statements is $CORRECT$?

The required amount of $KBr$ (molar mass $= 119 \, g/mol$) in grams to start the precipitation of $AgBr$ in $500 \, mL$ solution of $0.05 \, M \, AgNO_3$ will be ($K_{sp}$ of $AgBr = 5 \times 10^{-13}$)

In the circuit shown,the readings of the ammeter and voltmeter are $4\,A$ and $20\,V$ respectively. The meters are non-ideal. Then $R$ is:

An infinitely long straight conductor is bent into the shape as shown below. It carries a current of $I$ ampere and the radius of the circular loop is $R$ metre. Then,the magnitude of magnetic induction at the centre of the circular loop is