It is not correct to pray following the imam on the radio or TV

Shaykh Ibn ‘Uthaymeen was asked in Majmoo’ al-Fataawa
(15/213): can a Muslim – especially women – pray following a prayer that is
being transmitted via TV or radio without seeing the imam? 

He replied: 

It is not permissible for anyone to follow the imam via radio
or TV, because prayer in congregation means being together in the same
place, so it has to be in one place and the rows should be connected to one
another (i.e. immediately behind one another). It is not permissible to pray
via radio or TV because they do not meet these criteria. If we were to allow
that, anyone could pray all five prayers in his house, and Jumu’ah too. This
goes against the wisdom behind the prescription of Jumu’ah prayer and prayer
in congregation. Based on this, it is not permissible for women or anyone
else to pray following the radio or TV. And Allaah is the Source of
strength. 

The Standing Committee (9/218) was asked: 

Is it permissible for women to pray Jumu’ah prayer in their
houses, and all the other prayers, following the loudspeakers in the
village? Is it permissible for a sick person who cannot pray in the mosque
to follow the imam from his house through the loudspeaker? 

They replied: 

It is not permissible for men or women, weak or strong, to
pray in their houses, individually or in groups, following the prayer of the
imam in the mosque via the loudspeakers, whether that is an obligatory
prayer or supererogatory (naafil), Jumu’ah or any other prayer, whether
their houses are behind the imam or in front of him, because the obligatory
prayers must be offered in congregation in the mosque by men who are strong
and in good health, but women and men who are weak and in poor health are
excused from that duty. 

The Standing Committee was also asked about a woman praying
in her house, following the radio or TV, if she can hear the recitation and
takbeer, if that is an obligatory or naafil prayer. 

They replied: She is not permitted to do that, regardless of
whether it is an obligatory prayer or a naafil one, even if she can hear the
recitation and takbeer of the imam. 

Fataawa al-Lajnah al-Daa’imah li’l-Buhooth al-‘Ilmiyyah
wa’l-Ifta’, no. 6744.