Election FAQs: How do EVMs work?

As Mizoram, Chhattisgarh, Madhya Pradesh, Rajasthan, and Telangana go to polls this November here is all you need to know about the Electronic Voting Machine, or EVM and how it functions.

People who have voted in recent times are likely to be familiar with the EVM - which aids in both the casting and counting of votes. It is a white box with blue buttons and has a VVPAT machine attached to it.

Here's the lowdown on EVMs, starting with what the device actually is.

What is an EVM?

The electronic device that aids the voting process has two units - Control and Balloting. The former lies with the Presiding Officer or a Polling Officer while the latter is placed in the voting compartment.

Instead of issuing a ballot paper, the officer who is placed in charge of the Control unit releases a ballot by pressing the Ballot button on the Control unit. The two units are connected by a five-metre cable and once a ballot has been issued, voters can cast their vote by pressing the blue button on the Balloting unit.

Who designs and makes EVMs?

EVMs are designed and devised by the Technical Experts Committee of the ECI in collaboration with Bharat Electronics Ltd, Bangalore and Electronic Corporation of India Ltd, Hyderabad. The two public sector undertakings also manufacture EVMs.

Why use EVMs?

EVMs remove the possibility of casting 'Invalid Votes' which often exceeded the winning margin, in the past, numerous times and led to litigations. With EVMs a more accurate and authentic reflection of the choice of the electorate is possible. Moreover, they also reduce the time taken to count votes from an average of 30-40 hours during the paper ballot system to just 3 to 5 hours since things went electronic.

How many votes can be cast in an EVM?

A maximum of 2,000 votes can be recorded in an EVM.

How many candidates can an EVM cater to?

M2 EVMs (2006-2010) can cater to a maximum of 64 candidates including NOTA. There is a provision to cater to 16 candidates in the Balloting unit and if there are more candidates, an additional four Balloting units can be attached to ramp up the capacity to 64.

M3 EVMs (post-2013) can cater to a maximum of 384 candidates including NOTA, by connecting 24 Balloting units.

What happens if an EVM at a polling station goes out of order?

If an EVM at a polling station goes out of order, it is replaced with a new one. Polling does not have to begin from scratch since votes cast thus far remain in the memory of the Control unit. On counting day, votes from both Control units are counted to determine the result.

Can EVMs work without electricity?

India, which faces electricity issues, in some of its parts can still make use of EVMs there for polling purposes since they run on batteries. The design, which does away with external power connections to the devices, also ensures there is no chance of receiving an electric shock.

(Source: ECI Website)