1 Program to get the key of a min value from the dictionary:

sample_dict={
'Physics':82,
'math':65,
'history':75
}

print(min(sample_dict, key=sample_dict.get))

math

2 program to check if a value exists in a dictionary:

sample_dict={'a':100,'b':200,'c':300}
if 200 in sample_dict.values():
    print('200 present in a dict')

200 present in a dict

program to merge two dictionaries into one:

dict1={'ten':10,'twenty':20,'thirty':30}
dict2={'thirty':30,'fourty':40,'fifty':50}
print({**dict1, **dict2})

{'ten': 10, 'twenty': 20, 'thirty': 30, 'fourty': 40, 'fifty': 50}