If a unit vector is represented by $0.5\hat{i} - 0.8\hat{j} + c\hat{k}$,then the value of $c$ is:

In the given $LCR$ circuit,the voltage across the terminals of the resistance and the current in the circuit will be:

For the circle $C$ with the equation $x^2+y^2-16x-12y+64=0$,match the List-$I$ with the List-$II$ given below.

List-$I$	List-$II$
$(i)$ The equation of the polar of $(-5, 1)$ with respect to $C$	$(A)$ $y = 0$
$(ii)$ The equation of the tangent at $(8, 0)$ to $C$	$(B)$ $y = 6$
$(iii)$ The equation of the normal at $(2, 6)$ to $C$	$(C)$ $x + y = 7$
$(iv)$ The equation of the diameter of $C$ through $(8, 12)$	$(D)$ $13x + 5y = 98$
	$(E)$ $x = 8$

What will be the phase difference between virtual voltage and virtual current,when the current in the circuit is wattless (in $^o$)?

The transfer of energy from organism to organism in a natural community establishes

$A$ closely wound coil of $100$ turns and area of cross-section $1 \; cm^2$ has a coefficient of self-induction $1 \; mH$. The magnetic induction in the centre of the core of the coil when a current of $2 \; A$ flows in it will be (in $Wb/m^2$):