Which of the following is independent quantities is no used to specify the earth's magnetic field?

Which of the following is independent quantities is not used to specify the earth's magnetic field?

The earth's magnetic field is

Which of the following are independent on quantity of the gas ?

A vector needs three quantities for its specification. Name the three independent quantities conventionally used to specify the earth's magnetic field.

A vector needs three quantities for its specification. Name the three independent quantities conventionally used to specify the earth's magnetic field.

Answer the question regarding earth's magnetism: A vector needs three quantities for its specification. Name the three independent quantities conventionally used to specify the earth's magnetic field.