  The A/F-type stars and pulsators ($\delta$ Scuti-$\gamma$ Dor) are in a
critical regime where they experience the transition from radiative to
convective transport of energy in their envelopes. Such stars can pulsate in
both gravity and acoustic modes. Hence, the knowledge of their fundamental
parameters along with their observed pulsation characteristics can help in
improving the stellar models. When residing in a binary system, these pulsators
provide more accurate and less model dependent stellar parameters than in the
case of their single counterparts. We present a light curve model for the
eclipsing system KIC 6048106 based on the \textit{Kepler} photometry and the
code PHOEBE. We aim to obtain accurate physical parameters and tough
constraints for the stellar modelling of this intermediate-mass hybrid
pulsator. We performed a separate modelling of three light curve segments that
show a distinct behaviour due to a difference in activity. We also analysed the
\textit{Kepler} ETVs. KIC 6048106 is an Algol-type binary with F5-K5
components, a near-circular orbit and a 1.56-d period undergoing variations of
the order of $\frac{\Delta P}{P}\simeq 3.60\times10^{-7}$ in $287\pm7$ days.
The primary component is a main-sequence star with
$M_{1}=1.55\pm0.11M_{\odot}$,~$R_{1}=1.57\pm0.12R_{\odot}$. The secondary is a
much cooler subgiant with $M_{2}=0.33\pm0.07M_{\odot}$,~$R_{2}=1.77
\pm0.16R_{\odot}$. Many small near-polar spots are active on its surface. The
second quadrature phase shows a brightness modulation on a time scale $290\pm7$
days, in good agreement with the ETV modulation. This study reveals a stable
binary configuration along with clear evidence of a long-term activity of the
secondary star.
