Overview

A multi range current ammeter can be constructed by using a galvanometer circuit as shown in figure. We want a current meter that can measure 10 mA, 100 mA and 1A using a galvanometer of resistance 10 Ω and that produces maximum deflection for current 1 mA. Value of S₁ + S₂ + S₃ in ohms is

10 resistors, each of resistance R are connected in series to a battery of emf E and negligible internal resistance. Then those are connected in parallel to the same battery, the current is increased n times. The value of n is:

The resistance of platinum wire at $0^{?}\mathrm{C}$ is $2\mathrm{\Omega }$ and $6.8\mathrm{\Omega }$ at ${80}^{?}\mathrm{C}$ . The temperature coefficient of resistance of the wire is:

Three resistors having resistances r₁,r₂ and r₃ are connected as shown in the given circuit. The ratio i₂/i₃ of currents in terms of resistances used in the circuit is:

The effective resistance of a parallel connection that consists of four wires of equal length, equal area of cross-section and same material is 0.25Ω. What will be the effective resistance if they are connected in series?

Column -I gives certain physical terms associated with flow of current through a metallic conductor. Column - II gives some mathematical relations involving electrical quantities. Match Column - I and Column - II with appropriate relations.

In a potentiometer circuit a cell of EMF $1.5\mathrm{V}$ gives balance point at $36\mathrm{c}\mathrm{m}$  length of wire. If another cel) of EMF 2.5 V replaces the first cell, then at what length of the wire, the balance point occurs?

10 resistors, each of resistance $\mathrm{R}$ are connected in series to a battery of emf $\mathrm{E}$ and negligible internal resistance. Then those are connected in parallel to the samebattery, the current is increased $\mathrm{n}$ times. The value of $n$  is:

The resistance of platinum wire at $0^{\circ }\mathrm{C}$ is $2\mathrm{\Omega }$ and $6.8\mathrm{\Omega }$ at ${80}^{\circ }\mathrm{C}$ . The temperature coefficient of resistance of the wire is:

Resistance of a carbon resistor determined from colour codes is $(22000\pm 5\mathrm{\%})\mathrm{\Omega }$ The colour of third band must be: