$A$ gas expands isothermally against a constant external pressure of $1 \ bar$ from $10 \ dm^3$ to $20 \ dm^3$ by absorbing $800 \ J$ of heat from the surroundings. Calculate the value of $\Delta U$. (in $J$)

$A$ gas expands against a variable pressure given by $P = \frac{20}{V}$ ($P$ in $atm$ and $V$ in $L$). During expansion from volume of $1 \ L$ to $10 \ L$,the gas undergoes an increase in internal energy of $400 \ J$. How much heat is absorbed by gas during expansion (in $J$)? (Given: $1 \ L \cdot atm = 101.3 \ J$)

An ideal gas absorbs $210 \ J$ of heat and undergoes expansion from $3 \ L$ to $6 \ L$ against a constant external pressure of $10^5 \ Pa$. What is the value of $\Delta U$ (in $J$)?

$A$ gas performs $0.320 \ kJ$ work on the surrounding and absorbs $120 \ J$ of heat from the surrounding. Hence,the change in internal energy is: (in $J$)

If $100 \ L$ of gas is enclosed in a cylinder, absorbs $302.6 \ J$ of heat and expands to $200 \ L$ against a constant external pressure of $2 \ Pa$, calculate the internal energy change of the gas. (in $J$)

Which one of the following is applicable for an adiabatic expansion of an ideal gas?