UNITS
3 marks · NormalA student investigates an electromagnet. She measures a current of 2.0 amperes flowing through the coil when a voltage of 12.0 volts is applied.
State the SI unit for current.
State the SI unit for voltage.
Calculate the electrical power supplied to the coil. Give the unit.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) ampere or A
(b) volt or V
(c) 24 W
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · States 'ampere' or 'A' for current
B1 (b) · 1 mark · States 'volt' or 'V' for voltage
B1 (c) · 1 mark · Correct calculation: P = 2.0 A × 12.0 V = 24 W (accept correct unit) (follow-through)
Worked solution
a) The SI unit for current is the ampere (A). b) The SI unit for voltage is the volt (V). c) P = IV = 2.0 × 12.0 = 24 W