No, most Philips groomers cannot be used when connected to the power outlet (corded). Because many Philips grooming products can be used in the bath or shower, they will not switch on when connected to the power outlet for safety reasons.
Some Philips products (including some hair clipper models) are designed to be used only in dry conditions, and these can be used both corded and cordless. If you already have the product at home, refer to the user manual to find out if it can be used corded or simply connect it to the power outlet and try to switch it on (in dry conditions only). If it switches on when cordless but doesn't when corded, this is by design.
If you're considering buying a Philips groomer and want to know whether it can be used when connected to the power outlet, refer to the packaging or the information provided on the product page for more information.