When 1 coulomb of charge flows through a conductor in 1 sec, then the current passing through the conductor is:
A. 1HP
B. 1A
C. 1C
D. 1P

Hint: While doing electric circuit experiments in Physics lab, an ammeter (ampere-meter) is used to measure the flow of current. 1 Ampere is the transfer of charge of 1 Coulomb per second across a cross section.

Complete step by step answer:
1 Ampere is the base unit of electric current in the (SI) Standard International system of units. When one coulomb of charge flows through a conductor in one second then the current passing through the conductor is equal to 1 Ampere.
$\text{1Ampere=}\dfrac{\text{1Coulomb}}{\text{1second}}$
Hence, 1 Ampere is defined as the current passing through a conductor when 1 Coulomb of charge flows through it in 1 second.
The correct answer is option B. 1A

Additional Information:
Ampere can also be defined in terms of voltage and resistance as that current which, when passing through a resistance of 1 ohm, produces a potential difference of 1 V across its terminals.
Another precise definition of ampere in terms of electrons is, 1 Ampere is equivalent to $6.242\times {{10}^{18}}$electrons flowing through a conductor carrying constant current per second.

Note: The other options were not correct as 1HP is 1 Horsepower which is the unit of Power. 1HP = 746Watts. 1C is the SI unit of charge and 1P is not an SI unit for any physical quantity so they can’t be the answers either.