Physics of Electric Dipoles and Evaluation Criteria

The formula is $W = pE (cos \theta_0 - cos \theta_1)$.

The potential energy is maximum when the dipole moment $\mathbf{p}$ is antiparallel to the electric field $\mathbf{E}$, or when $\theta = 180°$.

The potential energy is given by $U(\theta) = - \mathbf{p} \cdot \mathbf{E}$, which can also be expressed as $U(\theta) = -pE cos \theta$.

<p>The torque is given by $\tau = pE sin \theta$.</p> Signup and view all the answers

<p>The potential energy of a dipole is at a minimum when $\theta = 0°$, which means the dipole moment is along the direction of the electric field.</p> Signup and view all the answers

<p>Marks should be awarded on the right-hand side for each part, and the total must be written in the left-hand margin and encircled.</p> Signup and view all the answers

<p>Marks should be awarded in the left-hand margin and encircled.</p> Signup and view all the answers

<p>The answer deserving more marks should be retained, while the other answer should be scored out with a note 'Extra Question'.</p> Signup and view all the answers

<p>No marks should be deducted for cumulative errors; they should be penalized only once.</p> Signup and view all the answers

<p>A full scale of marks from 0 to 70 must be utilized.</p> Signup and view all the answers

<p>Examiners should avoid leaving answers unassessed, giving incorrect marks, and wrong totaling.</p> Signup and view all the answers

<p>It should be marked with a cross (X) and awarded zero (0) marks.</p> Signup and view all the answers

<p>Examiners must evaluate 20 answer books per day in main subjects and 25 in other subjects.</p> Signup and view all the answers

<p>The power of one part of the lens will be $2P$.</p> Signup and view all the answers

<p>The power of the combination will be $2P$.</p> Signup and view all the answers

<p>The power of the combination will be $0$.</p> Signup and view all the answers

<p>The power of the combination is $15 D$.</p> Signup and view all the answers

<p>The formula is $P = 1/f$ where $f$ is the focal length in meters.</p> Signup and view all the answers

<p>The focal length of each part becomes half that of the original lens.</p> Signup and view all the answers

<p>The resulting power will be $2P$.</p> Signup and view all the answers

<p>A smaller radius of curvature leads to a higher lens power.</p> Signup and view all the answers

<p>The kinetic energy of emitted photoelectrons increases with the increase in the intensity of the incident light.</p> Signup and view all the answers

<p>The flux linkage between the two coils is maximum when they are wound on each other.</p> Signup and view all the answers

<p>The two wires, when carrying current in the same direction, attract each other and move apart.</p> Signup and view all the answers

<p>No, plane and convex mirrors cannot produce real images under any circumstance.</p> Signup and view all the answers

<p>Photoelectric current depends on the wavelength of the incident light.</p> Signup and view all the answers

<p>This illustrates the fundamental electromagnetic principle that like currents repel each other, while opposite currents attract.</p> Signup and view all the answers

<p>Using the wave speed equation, the wavelength can be determined, suggesting a relationship between frequency and wavelength.</p> Signup and view all the answers

<p>When the current direction is reversed, the wires repel each other, demonstrating the effects of electromagnetic forces.</p> Signup and view all the answers

<p>The formula is $R = R_0 [1 + eta (T - T_0)]$.</p> Signup and view all the answers

<p>The final temperature $T$ is $270°C$.</p> Signup and view all the answers

<p>The wavelength is $600 nm$ or $6×10^{-7} m$.</p> Signup and view all the answers

<p>The wavelength in the medium is $400 nm$ or $4×10^{-7} m$.</p> Signup and view all the answers

<p>In this context, $R$ represents the radius of the curved surface.</p> Signup and view all the answers

<p>The radius $R$ is $6.4 cm$.</p> Signup and view all the answers

<p>$R_1$ and $R_2$ are the radii of curvature for the two surfaces of a lens or mirror.</p> Signup and view all the answers

<p>The refractive index inversely affects the wavelength; as $μ$ increases, wavelength decreases.</p> Signup and view all the answers

<p>Flux leakage, resistance of the windings, and eddy currents.</p> Signup and view all the answers

<p>Current changes correspondingly, so the input power is equal to the output power.</p> Signup and view all the answers

<p>Vs = 1350 V.</p> Signup and view all the answers

<p>IP = 30 A.</p> Signup and view all the answers

<p>The minimum deviation angle is defined as the angle at which the angle of incidence equals the angle of emergence.</p> Signup and view all the answers

<p>n = sin(A + δ) / sin(A).</p> Signup and view all the answers

<p>The refracted ray becomes parallel to the base of the prism.</p> Signup and view all the answers

<p>Understanding energy losses is crucial for improving efficiency and performance of electrical systems.</p> Signup and view all the answers