Which unit is equivalent to Joules per second?

The unit that is equivalent to Joules per second is the Watt. This is because a Watt is defined as one Joule of energy transferred or converted per second of time. This relationship highlights the concept of power, where power is the rate at which work is done or energy is transferred.

To understand this in context, consider that in electrical systems, power is calculated as the product of voltage (in volts) and current (in amperes). Since 1 Watt equals 1 Joule per second, when electrical energy flows through a circuit, it describes the amount of energy used or produced over time in a concise way.

This direct connection to energy and time illustrates why the Watt is the correct answer. Other options represent different physical concepts: Volts measure electric potential, Newtons measure force, and Lumens measure luminous flux, none of which directly relate to the concept of power as defined by Joules per second.