Consider an atomic gas with number density \( n = 10^{20} \, \text{m}^{-3} \), in the ground state at 300 K. The valence electronic configuration of atoms is \( f^7 \). The paramagnetic susceptibility of the gas \( \chi = m \times 10^{-11} \). The value of \( m \) (rounded off to two decimal places) is \(\underline{\hspace{2cm}}\).
(Given: Magnetic permeability of free space \( \mu_0 = 4\pi \times 10^{-7} \, \text{H m}^{-1} \), Bohr magneton \( \mu_B = 9.274 \times 10^{-24} \, \text{A m}^2 \), Boltzmann constant \( k_B = 1.3807 \times 10^{-23} \, \text{K}^{-1} \))
The figure shows an opamp circuit with a 5.1 V Zener diode in the feedback loop. The opamp runs from \( \pm 15 \, {V} \) supplies. If a \( +1 \, {V} \) signal is applied at the input, the output voltage (rounded off to one decimal place) is:
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:
In the transistor circuit shown in the figure, \( V_{BE} = 0.7 \, {V} \) and \( \beta_{DC} = 400 \). The value of the base current in \( \mu A \) (rounded off to one decimal place) is: