List of top Physics Questions on Resistance and Resistivity

Determine the current in the \( 3 \, \Omega \) branch of a Wheatstone Bridge in the circuit shown in the figure.
A current of \( 4.0 \, \text{A} \) flows through a wire of length \( 1 \, \text{m} \) and cross-sectional area \( 1.0 \, \text{mm}^2 \), when a potential difference of \( 2 \, \text{V} \) is applied across its ends.
Calculate the resistivity of the material of the wire.
An electric iron rated \( 2.2 \, \text{kW}, 220 \, \text{V} \) is operated at \( 110 \, \text{V} \) supply. Find:
its resistance, and
heat produced by it in 10 minutes.
The resistance of a metal wire at \( 20^\circ \text{C} \) is \( 1.05 \, \Omega \) and at \( 100^\circ \text{C} \) is \( 1.38 \, \Omega \). Determine the temperature coefficient of resistivity of this metal.
Derive the condition for which a Wheatstone Bridge is balanced.
A wire of resistance 4 \(\Omega\) is used to make a coil of radius 7 cm. The wire has a diameter of 1.4 mm and the resistivity of its material is 2 x 10\(^{-7}\) \(\Omega\) m. The number of turns in the coil will be
Resistivity of a conductor depends on
The ends of six wires, each of resistance R (= 10 \(\Omega\)) are joined as shown in the figure. The points A and B of the arrangement are connected in a circuit. Find the value of the effective resistance offered by it to the circuit.
The ends of six wires, each of resistance

A wire of length and resistance \(100\) is divided into 10 equal parts. The first \(5\) parts are connected in series while the next \(5\) parts are connected in parallel. The two combinations are again connected in series. The resistance of this final combination is:

The terminal voltage of the battery, whose emf is\(10V\) and internal resistance\(1Ω\), when connected through an external resistance of \(4Ω\) as shown in the figure is:
 

A cell of constant emf is first connected to a resistance \(R_1\) and then to \(R_2\). If power delivered in both cases are same, then the internal resistance of the cell is: