Consider the following statements and select the correct ones.
I. Most of the electrical devices we use require ac voltage.
II. Most of the electrical energy sold by power companies is transmitted and distributed as alternating current.
III. AC voltage can be easily and efficiently converted from one voltage to another by means of transformers.
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → I, II and III are correct
I. Most of the electrical devices we use require ac voltage. — True. The mains supply in homes and offices is an alternating voltage, and most devices are built to run on it.
II. Most of the electrical energy sold by power companies is transmitted and distributed as alternating current. — True. Power companies supply energy as ac, which is why the devices are made to work on ac voltage.
III. AC voltage can be easily and efficiently converted from one voltage to another by means of transformers. — True. A transformer works only with a changing current. It can step an ac voltage up or down with little loss. This is the main reason ac is preferred over dc.
NCERT (2026-27):
Introduction – “… Today, most of the electrical devices we use require ac voltage. This is mainly because most of the electrical energy sold by power companies is transmitted and distributed as alternating current. The main reason for preferring use of ac voltage over dc voltage is that ac voltages can be easily and efficiently converted from one voltage to the other by means of transformers.”