Actually it is far more effective to use more weapons than it is to use one big bomb. This is mostly because the destructive power of a warhead is proportional to the cube root of its explosive power - in other words, to double the destructive power one has to increase the explosive power by a factor of eight.
More than that…
A lot of the bigger bomb’s explosive power will just go into digging a deeper hole as well as be expended up and away from what you want to flatten. So, a lot of that extra energy is “wasted” inasmuch as it is not flattening buildings. Far better, assuming you want to flatten a big city, to use multiple bombs with overlapping circles of effect.
I think part of the push for BIG bombs in the past was the inaccuracy of the missiles. First, you may not have had lots and lots of missiles and second they may have had an accurate strike area measured in miles or more. With a really BIG bomb that can be close enough. Once accuracy improved you could get far better results from multiple missiles (also a better chance at least one will make it and work…with one bomb if it fritzes out that’s it).
I once read (dunno if it is true) the Soviets had at least five warheads pointed at most major US cities. So, five each for New York, LA, Washington, Chicago, Dallas, Miami, etc…
…So what you’re saying is that Israel has Schrödinger’s bomb? Does Schrödinger know?
Puts a any altogether different meaning to “open the box and find out.” 
I never really bought into the “deterrence” thing at least for Israel. Oh it makes sense for sure, but Sadat has written that after the US came and resupplied Israel in the Yom Kippur War he realized that the USA would never allow Israel to be “destroyed” and he accepted this and started negotiations to get his land back.
It was the US backing not the nukes (Which everyone knew Israel had even back then) that got Egypt to the negotiation tables. Indeed the best offense tactic Israel has against Egypt is not a nuke but destroying the Aswan Dam and letting it flood the Nile Valley.
Currently the only declared Hydrogen Bomb powers are those which have permanent UN Security Council Seats: USA, Russia, UK, France and China.
Though India started it’s nuclear program to ward off China (remember they fought a brief war during the 60s), it is now more aimed at Pakistan, which developed its own.
Pakistan has told both Libya and Iraq to “buzz off” and make their own nukes when both nations tried to get Pakistan to sell them one or to at least give them the materials needed.
The “Muslim A-Bomb” has now turned into a “Arab-A-Bomb” type of thing and is mostly for prestige value.
The “100-megaton” hydrogen bomb never was militarily practical even at the time the Soviets built it. The test version was only 50 megatons because it left off the U-238 tamper that would have doubled the yield AND added as much fallout to the atmosphere as all previous tests combined. It was too heavy to be delivered by any ICBM ever fielded and for the test drop was carried in a bomber hanging halfway out the bomb bay doors because of it’s diameter. It only made sense if there was a military need to deliver the absolute maximum destruction with one single bomb, and by the time it was built improved designs and greater stocks of fissionables had moderated the need to get the maximum yield out of each fission trigger. As mentioned upthread, the square-cube law means that bigger bombs give you proportionally less damage.
He might, and he might not.
Actually, the best offensive tactic Israel has against Egypt is destroying the Aswan dam with a nuke and letting it flood the Nile Valley with radioactive water.
One surmises these warheads are MIRVs (one missile launched, several warheads make re-entry), so assuming the 5 missile figure is legit, the actual warhead count would be more like 25-35. Remember to hide under a desk !
In 1973, the Egyptian aims were never to “destroy Israel” or even to get Sinai back, but were to prove that holding the territory was impractical for Israel.