# Ampere unit

### Ampere definition

So Ampere or amp (symbol: A) is the unit of electrical current.

So The Ampere unit is named after Andre-Marie Ampere, from France.

One Ampere is defined as the current that flows with electric charge of one Coulomb per second.

1 A = 1 C/s

### Amperemeter

So The Ampere meter or ammeter is an electrical instrument that is used to measure electrical current in amperes.

When we want to measure the electrical current on the load, the ampere-meter is connected in series to the load.

So The resistance of the ampere-meter is near zero, so it will not affect the measured circuit.

### Table of ampere unit prefixes

namesymbolconversionexample
microampere (microamps)μA1μA = 10-6AI = 50μA
milliampere (milliamps)mA1mA = 10-3AI = 3mA
ampere (amps)A

-

I = 10A
kiloampere (kiloamps)kA1kA = 103AI = 2kA

### How to convert amps to microamps (μA)

So The current I in microamperes (μA) is equal to the current I in amperes (A) divided by 1000000.

I(μA) = I(A) / 1000000

#### Example 1

How to convert 15 Amps to microAmps:

A(µA) = 15A × 106 = 15000000 µA

#### Example 1

How to convert 20 Amps to microAmps:

A(µA) = 15A × 106 = 20000000 µA

### How to convert amps to milliamps (mA)

So The current I in milliamperes (mA) is equal to the current I in amperes (A) divided by [1000].

I(mA) = I(A) / 1000

#### Example 1

Convert current of 25 amps to milliamps:

The current I in milliamps (mA) is equal to 25 amps (A) times 1000mA/A:

I(mA) = 25A × 1000mA/A = 25000mA

#### Example 2

Convert current of 35 amps to milliamps:

The current I in milliamps (mA) is equal to 3 amps (A) times 1000mA/A:

I(mA) = 35A × 1000mA/A = 35000mA

### How to convert amps to kiloamps (kA)

So The current I in kiloamperes (mA) is equal to the current I in amperes (A) times [1000].

I(kA) = I(A) ⋅ 1000

#### Example  1

How to convert 7,000 amperes to kiloamperes using the formula above.

7,000 A = (7,000 ÷ 1,000) = 7 kA

#### Example  2

How to convert 9,000 amperes to kiloamperes using the formula above.

9,000 A = (9,000 ÷ 1,000) = 9 kA

### How to convert amps to watts (W)

So The power P in watts (W) is equal to the current I in amps (A) times the voltage V in volts (V).

P(W) = I(A) ⋅ V(V)

#### Example 1

What is power consumption in watts when the current is 6A and the voltage supply is 110V?

Answer: the power P is equal to current of 6 amps times the voltage of 110 volts.

P = 6A × 110V = 660W

#### Example 2

What is power consumption in watts when the current is 10A and the voltage supply is 110V?

Answer: the power P is equal to current of 10 amps times the voltage of 110 volts.

P = 10A × 110V = 1,100W

### How to convert amps to volts (V)

The voltage V in volts (V) is equal to the power P in watts (W) divided by the current I in amperes (A):

V(V) = P(W) / I(A)

#### Example 1

What is the voltage supply of an electrical circuit that has power consumption of 45 watts and current flow of 6 amps?

The voltage V is equal to 45 watts divided by 6 amps:

V = 45W / 6A = 7.5V

#### Example 2

What is the voltage supply of an electrical circuit that has power consumption of 45 watts and current flow of 10 amps?

The voltage V is equal to 45 watts divided by 10 amps:

V = 45W / 10A = 4.5V

The voltage V in volts (V) is equal to the current I in amperes (A) times the resistance R in ohms (Ω):

V(V) = I(A) ⋅ R(Ω)

#### Example 1

What is the voltage supply of an electrical circuit that has current flow of 3 amps and resistance of 16 ohms?

According to ohm's law the voltage V is equal to 3 amps times 16 ohms:

V = 3A × 16Ω = 48V

#### Example 2

What is the voltage supply of an electrical circuit that has current flow of 3 amps and resistance of 20 ohms?

According to ohm's law the voltage V is equal to 3 amps times 20 ohms:

V = 3A × 20Ω = 60V

### How to convert amps to ohms (Ω)

The resistance R in ohms (Ω) is equal to the voltage V in volts (V) divided by the current I in amperes (A):

R(Ω) = V(V) / I(A)

#### Example 1

What is the resistance of an electrical circuit that has voltage supply of 12 volts and current flow of 0.2 amp?

The resistance R is equal to 12 volts divided by 0.2 amp:

R = 12V / 0.2A = 60Ω

### How to convert amps to kilowatts (kW)

The power P in kilowatts (kW) is equal to the current I in amps (A) times the voltage V in volts (V) divided by 1000:

P(kW) = I(A) ⋅ V(V) / 1000

#### Example 1

What is power consumption in kW when the current is 5A and the voltage supply is 110V?

Answer: the power P is equal to current of 5 amps times the voltage of 110 volts, divided by 1000.

P = 5A × 110V / 1000 = 0.55kW

### How to convert amps to kilovolt-ampere (kVA)

The apparent power S in kilovolt-amps (kVA) is equal to RMS current IRMS in amps (A), times the RMS voltage VRMS in volts (V), divided by 1000:

S(kVA) = IRMS(A) ⋅ VRMS(V) / 1000

### How to convert amps to coulombs (C)

The electric charge Q in coulombs (C) is equal to the current I in amps (A), times the time of current flow t in seconds (s):

Q(C) = I(A) ⋅ t(s)