Electricity and Resistance Quiz

<p>It is only applicable to metallic conductors. (C)</p> Signup and view all the answers

<p>Resistance decreases with temperature. (A)</p> Signup and view all the answers

<p>Electric intensity is the amount of electric field strength per unit charge experienced by a test charge. Its SI unit is volt per meter (V/m) and its dimensions are [M L T^{-3} I^{-1}].</p> Signup and view all the answers

<p>Coulomb's law states that the force between two point charges is directly proportional to the product of their magnitudes and inversely proportional to the square of the distance between them. The force in vector form can be obtained using the equation $\mathbf{F} = \frac{1}{4\pi\varepsilon_0} \frac{q_1 q_2}{r^2} \mathbf{\hat{r}}$, where $\varepsilon_0$ is the permittivity of free space, $q_1$ and $q_2$ are the magnitudes of the charges, $r$ is the distance between them, and $\mathbf{\hat{r}}$ is the unit vector in the direction from $q_1$ to $q_2$.</p> Signup and view all the answers

<p>Specific resistance, also known as resistivity, is a measure of the resistance offered by a material to the flow of electric current. It is defined as the resistance of a conductor of unit length and unit cross-sectional area. Its SI unit is ohm-meter (Ω·m).</p> Signup and view all the answers

<p>The limitations of Ohm's law are as follows: 1) It is not applicable to all materials, especially non-ohmic materials like diodes and transistors. 2) It assumes that the temperature remains constant, but the resistance of most conductors increases with temperature. 3) It assumes that the physical dimensions of the conductor remain constant, but the resistance of a wire increases with its length and decreases with its cross-sectional area. 4) It assumes that the voltage is directly proportional to the current, but in some cases, the relationship may be nonlinear.</p> Signup and view all the answers

<p>The effect of temperature on resistance depends on the material. In most conductors, an increase in temperature leads to an increase in resistance. This is because as the temperature increases, the atoms or ions in the conductor vibrate more vigorously, impeding the flow of electrons. In some materials, such as semiconductors, the resistance decreases with an increase in temperature due to the increased availability of charge carriers.</p> Signup and view all the answers