Why do so many UK electrical sockets have an on/off switch next to them?

the UK power grid is weird. mostly due to echoes of the war. used to be that, to save copper, the entire house and sometimes multiple houses on a street would be wired as one big loop of wire, no fuse box or anything. that's where the individually fused plugs and switched sockets come from. then, since it turned out to be quite a good idea for safety, they kept doing it.

Allows you to remove power from the plugged in device without unplugging it. This provides convenience to easily and quickly turn things on and off and prevents arcing when unplugging. 240V 13A can arc a bit, particularly if unplugged under load, or on older sockets where the contacts have worn. While a little arcing doesn't do much damage immediately, over time it will cause pitting and make a high resistance joint that will generate heat.

The switch only disconnects the live terminal, but the neutral terminal should be similar potential to earth (depending on how the building is wired).

Truly the king of plugs and sockets. The plugs are individually fused according to the device needs, ergonomic to use and exciting to stand on.

So we can turn the power on and off.

Why else would you have a switch next to a power socket?

To turn things on and off.

To turn them on and off.

This is virtually standard in Australia

I like them, personally. You don't have to use them but they are sometimes handy. I just spent 30 seconds feeling around a TV to turn it off only to discover it doesn't have buttons. Killed it at the wall.

It's not a deal breaker, in any case. The weird foreign convention I would like to shame is doors that require a key to open from the inside.

Safety, easier to switch things off without unplugging them. Why not have one if it's more convenient? Not all of them have switches though.

As any cautious parent could tell you, these are helpful when the toddler starts sticking things in places where they don't belong. Such as metal cutlery. In the power sockets.

Kind of off topic, but I've just gotta add that the safety shutters over the positive and negative terminals that only open when the ground pin (which is longer than the others on the plug) is inserted up top is brilliant, it basically makes short circuiting impossible. Electrical outlet design is one of the few things I'll concede the UK does better than the rest of the world.

UK household electricity is pretty spicy compared to many other places - it has more safety features as a result. (3 pinned fused plug, socket switches etc)

I present to you my favorite YouTube person:

The GFCI/RCD, a simple but life saving protector:

https://youtu.be/ILBjnZq0n8s?list=PLv0jwu7G_DFU62mIGZNag5vQ0a6tDGBpO

In defense of the Switched Outlet:

https://youtu.be/2DGqVbTHX-k

Electrical topics playlist:

https://youtube.com/playlist?list=PLv0jwu7G_DFU62mIGZNag5vQ0a6tDGBpO

I could just watch this guy all day lol

Great for turning off a device or several devices without having to unplug (e.g. if the sockets are behind a bookcase, this is much more convenient). Not a super common need but when it saves moving furniture it helps. Given that UK switches are tougher to plug in and unplug than most (due to safety features), I prefer using a switch. Also, the switches are cheap and give more options, so may as well!

I rely on one for a light where the switch broke and wasn't easily replaceable, so being able to fall back on the mains switch meant I can keep using the light.

I like the integration of the switch, should be standard. I use many switch plug-ins just to avoid stand-by consumption (it really adds up over the year) and to avoid high pitch humming on some devices.

YSK: there's also remote controls for these switches, very handy

Being a uk person its cause they can & its also in to building / electric code. Its just a switch that breaks the live leg, stops sparking when plugging in stuff.

"so many"?

isn't it all of them?

Everything you'd want to know about British wiring and my introduction to Tom Scott:

https://youtu.be/UEfP1OKKz_Q

No one seemed to mention the important fact that UK and I think most Europe is a higher voltage than the US. Tom Scott as well as Technology Connections have some good videos on the whys and differences it causes.

Safety and convenience versus the cost of including them, I expect.

The Wikipedia page for BS 1363 says they're optional and weren't added to the standard until 1967. I can't recall having seen a domestic socket without one.

But it seems the only legal way to read the actual standard is to pay for it, and even the HSE website isn't much help.

Having grown up with it I missed those tbh. Makes saving power easier lol

when any electricity leaks out (for example through your body) it switches off. the eu also has the same system, but its one switch for your entire house. the us also has this but only in bathrooms.

in America many houses have the on off switches with the lights on the other side of the room for lamps etc

also small child/baby protection.

at least in part it's an end result of decades of crud and tech debt, so to speak, accumulating in british power grid and home wiring. they do it this way because otherwise it won't be safe. continental euro home wiring usually has thicker wires, residual-current circuit breakers and no ring circuits so we get away without fuzes and switches, and with smaller plugs that don't become caltrops. sometimes we do have ring circuits kind of thing, but not in house wiring, instead it's in medium voltage distribution grid, and it's sized so that it can serve most of loads after single failure.

For safety I guess?

Not positive but those could be GFI outlets.

All plug points in India also have (regular sized, not these tiny ones) switches to control them

Edit: The usage and benefits are the most obvious ones that you would imagine