Yes, they can. You have the right to refuse the information, but it could lead to your not receiving full benefits for the illness or time taken.
they can but really it's none of their business. It's actually quite rude. They should not have to know wether or why you are calling in sick
Yes they can tell you that you have to come in.
They can ask you to elaborate and even ask for a doctors note
Certainly. The rules for sick leave are decided by the employer and are unregulated. Employers need not accept doctors' notes.
To my knowledge, employers can ask about your attendance. They are NOT permitted to ask why you were out of the office. They are NOT permitted to ask questions about your religious or sexual orientations. They are not permitted to ask specifics about whether or not the previous employer thinks you are ugly or a liar or whatever. If the potential employer does ask these, you can file a lawsuit. If the previous employer makes untruthful, slanderous statements about you, you can also file a lawsuit.
They can try to call them, but the doctor is not allowed to give out any information about you. The doctor might be able to say "yes s/he came in today"/"no s/he didn't come in". But the doctor is not allowed to give out the reason why you went in, since this would be a breach of the Doctor-Patient Confidentiality and therefore illegal. In summary- The doctor can say whether you have seen him/her on that day. But the doctor cannot tell the employer why, if you did, you went to see the doctor, unless the doctor has your permission to do so.
can a employer contact you while you are covered by a sick note
It depends on the employer's sick leave policies.
No the employer will have to give you sick leave once a year .
He can for the day that you claimed to be sick.
YES
Answer Any employer can find what you made at your last job by calling them to find out.
Sick pay is unregulated. It is a gift from some employers, and the rules are whatever the employer says.