A wire of resistance 0.2 \( \Omega/{cm} \) is bent to form a square ABCD of side 10 cm. A similar wire is connected between the corners B and D. If 2 V battery is connected across A and C, the power dissipated is
First, calculate the total resistance of the square: - The side length of the square is 10 cm, so the total resistance of the square formed by the wire is: \[ R_{{square}} = 0.2 \, \Omega/{cm} \times 10 \, {cm} = 2 \, \Omega \] Now, consider the wire connected between B and D. The total resistance in the path from A to C is calculated by combining the resistances in series and parallel. Using Ohm's law: \[ P = \frac{V^2}{R} \] Substituting the values: \[ P = \frac{2^2}{2} = 2 \, {W} \] Thus, the power dissipated is 2 W.
Final Answer: 2 W.
Einstein's Explanation of the Photoelectric Effect:
Einstein explained the photoelectric effect on the basis of Planck’s quantum theory, where light travels in the form of small bundles of energy called photons.
The energy of each photon is hν, where:
The number of photons in a beam of light determines the intensity of the incident light.When a photon strikes a metal surface, it transfers its total energy hν to a free electron in the metal.A part of this energy is used to eject the electron from the metal, and this required energy is called the work function.The remaining energy is carried by the ejected electron as its kinetic energy.