You recently got a minimum wage job in California. You expected to be paid $16.50 per hour. Even that is going to be difficult on your budget. The cost of living is very high in California, so simply paying the rent is a much greater expense than it would be in other states. But you believed that $16.50 per hour should be enough, which is why you accepted the job.
It is also why you are so concerned when you receive your first paycheck and discover that your boss is only paying you $7.25 per hour. It is less than half of what you expected. There is no way you are going to be able to make your budget work, and you feel that you have been deceived or tricked into accepting such a low pay rate.
When you confront your boss, though, they bring up the federal minimum wage statute. It says the federal minimum wage is $7.25 an hour, and so that is what they have decided to pay you. Is this legal?
The higher wage generally applies
There are some exceptions, but they are rare. For most employees in California, the higher of the two minimum wages has to apply. Even though federal minimum wage is $7.25 an hour, your employer is likely obligated to pay you $16.50 an hour to be in line with California law.
Things can be a bit different in other states. For example, South Carolina has no minimum wage at all. This means that the federal minimum wage applies, so $7.25 is all that someone is obligated to pay. But in states that have their own minimum wage, if it is higher than the federal level, they must pay the higher wage.
If you are being paid improperly and you fear you are experiencing wage theft, be sure you know what legal steps to take.

