Example of a biodegradable polymer pair is

An electrochemical cell is fueled by the combustion of butane at $1$ bar and $298 K$ . Its cell potential is $\frac{ X }{ F } \times 10^3$ volts, where $F$ is the Faraday constant. The value of $X$ is $...$ .
Use : Standard Gibbs energies of formation at $298 K$ are : $\Delta_f G_{ CO _2}^{ o }=-394 kJ mol ^{-1}; \Delta_f G_{\text {water }}^{ o }=-237 kJ mol ^{-1} ; \Delta_f G_{\text {butane }}^{ o }=-18 kJ mol ^{-1}$

If the tangent at point $(1, 2)$ on the curve $y = ax^2 + bx + \frac{7}{2}$ is parallel to the normal at point $(-2, 2)$ on the curve $y = x^2 + 6x + 10$,then:

The work done in moving an object from the origin to a point whose position vector is $r = 3 \hat{i} + 2 \hat{j} - 5 \hat{k}$ by a force $F = 2 \hat{i} - \hat{j} - \hat{k}$ is:

The angle between the asymptotes of the hyperbola $x^2-3y^2=3$ is

Choose the correct statement$(s)$:
$(A)$ The position of the centre of mass of a system is dependent on the choice of the coordinate system.
$(B)$ Newton's second law of motion is applicable to the centre of mass of the system.
$(C)$ Internal forces cannot change the state of the centre of mass.
$(D)$ Internal forces can change the state of the centre of mass.