The resistance of the meter bridge AB in given figure is 4 $$\Omega $$. With a cell of emf $$\varepsilon $$ = 0.5 V and rheostat resistance R_h = 2 $$\Omega $$ the null point is obtained at some point J. When the cell is replaced by another one of emf $$\varepsilon $$ = $$\varepsilon $$₂ the same null point J is found for R_h = 6 $$\Omega $$. The emf $$\varepsilon $$₂ is, :

In a Wheatstone bridge(see fig.), Resistances P and Q are approximately equal. When R = 400 $$\Omega $$, the bridge is balanced. On interchanging P and Q, the value of R, for balance, is 405 $$\Omega $$. The value of X is close to :

A current of 2 mA was passed through an unknown resistor which dissipated a power of 4.4 W. Dissipated power when an ideal power supply of 11 V is connected across it is -

The Wheatstone bridge shown in figure, here, gets balanced when the carbon resistor used as R₁ has the colour code (Orange, Red, Brown). The resistors R₂ and R₄ are 80$$\Omega $$ and 40$$\Omega $$, respectively. Assuming that the colour code for the carbon resistors gives their accurate values, the colour code for the carbon resistor, used as R₃, would be -