An \( \alpha \) particle is scattered from an Au target at rest as shown in the figure. \( D_1 \) and \( D_2 \) are the detectors to detect the scattered \( \alpha \) particle at an angle \( \theta \) and along the beam direction, respectively, as shown. The signals from \( D_1 \) and \( D_2 \) are converted to logic signals and fed to logic gates. When a particle is detected, the signal is 1 and is 0 otherwise. Which one of the following circuits detects the particle scattered at the angle \( \theta \) only?

Step 1: The logic gates are used to detect the particle that is scattered at angle \( \theta \) only. For this, the signal from both detectors \( D_1 \) and \( D_2 \) need to be simultaneously 1, which occurs when both detectors register a signal. This can be done using the AND gate logic.
Step 2: In the AND configuration, both \( D_1 \) and \( D_2 \) must detect the particle for the output to be 1, which corresponds to the particle being scattered at the desired angle \( \theta \). If either of the detectors does not register the particle, the output will be 0.
The output (Y) of the given logic implementation is similar to the output of an/a …………. gate.
Consider the following logic circuit.
The output is Y = 0 when :


To obtain the given truth table, the following logic gate should be placed at G:
A wheel of mass \( 4M \) and radius \( R \) is made of a thin uniform distribution of mass \( 3M \) at the rim and a point mass \( M \) at the center. The spokes of the wheel are massless. The center of mass of the wheel is connected to a horizontal massless rod of length \( 2R \), with one end fixed at \( O \), as shown in the figure. The wheel rolls without slipping on horizontal ground with angular speed \( \Omega \). If \( \vec{L} \) is the total angular momentum of the wheel about \( O \), then the magnitude \( \left| \frac{d\vec{L}}{dt} \right| = N(MR^2 \Omega^2) \). The value of \( N \) (in integer) is:

A point charge \( q \) is placed at a distance \( d \) above an infinite, grounded conducting plate placed on the \( xy \)-plane at \( z = 0 \).
The electrostatic potential in the \( z > 0 \) region is given by \( \phi = \phi_1 + \phi_2 \), where:
\( \phi_1 = \frac{1}{4 \pi \epsilon_0} \cdot \frac{q}{\sqrt{x^2 + y^2 + (z - d)^2}} \)
\( \phi_2 = - \frac{1}{4 \pi \epsilon_0} \cdot \frac{q}{\sqrt{x^2 + y^2 + (z + d)^2}} \)
Which of the following option(s) is/are correct?
Two projectile protons \( P_1 \) and \( P_2 \), both with spin up (along the \( +z \)-direction), are scattered from another fixed target proton \( T \) with spin up at rest in the \( xy \)-plane, as shown in the figure. They scatter one at a time. The nuclear interaction potential between both the projectiles and the target proton is \( \hat{\lambda} \vec{L} \cdot \vec{S} \), where \( \vec{L} \) is the orbital angular momentum of the system with respect to the target, \( \vec{S} \) is the spin angular momentum of the system, and \( \lambda \) is a negative constant in appropriate units. Which one of the following is correct?
