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.
Given below are two statements: one is labelled as Assertion (A) and the other one is labelled as Reason (R).
Assertion (A): Emission of electrons in the photoelectric effect can be suppressed by applying a sufficiently negative electron potential to the photoemissive substance.
Reason (R): A negative electric potential, which stops the emission of electrons from the surface of a photoemissive substance, varies linearly with the frequency of incident radiation.
In light of the above statements, choose the most appropriate answer from the options given below:

Which of the following statements are correct, if the threshold frequency of caesium is $ 5.16 \times 10^{14} \, \text{Hz} $?
If the roots of $\sqrt{\frac{1 - y}{y}} + \sqrt{\frac{y}{1 - y}} = \frac{5}{2}$ are $\alpha$ and $\beta$ ($\beta > \alpha$) and the equation $(\alpha + \beta)x^4 - 25\alpha \beta x^2 + (\gamma + \beta - \alpha) = 0$ has real roots, then a possible value of $y$ is: