In the balanced condition, the values of the resistances of the four arms of a Wheatstone bridge are shown in the figure below. The resistance R₃ has temperature coefficient 0.0004$$^\circ$$C^-1. If the temperature of R₃ is increased by 100$$^\circ$$C, the voltage developed between S and T will be ________ volt.

A parallel plate capacitor of capacitance C has spacing d between two plates having area A. The region between the plates is filled with N dielectric layers, parallel to its plates, each with thickness, $$\delta = {d \over N}$$. The dielectric constant of the m^th layer is $${K_m} = K\left( {1 + {m \over N}} \right)$$. For a very large N(>10³), the capacitance C is $$\alpha \left( {{{K{\varepsilon _0}A} \over {d\ln 2}}} \right)$$

The value of $$\alpha $$ will be ..................

[$$ \in $$₀ is the permittivity of free space.]

In the following circuit, the current through the resistor R(=2$$\Omega$$) is I amperes. The value of I is :

A galvanometer gives full scale deflection with 0.006 A current. By connecting it to a 4990 $$\Omega$$ resistance, it can be converted into a voltmeter of range 0-30V. If connected to a $${{2n} \over {249}}\Omega $$ resistance, it becomes an ammeter of range 0-1.5 A. The value of n is