It's not silver, it's made of copper-nickel like all other nickels except the WWII ones with a large mint mark above the dome of Monticello.
There's more information at the Related Question.
The coin is called an Indian Head nickel or a buffalo nickel, not "buffalo head" - after all, it shows the entire buffalo! Please see the question "What is the value of a 1934 US nickel?" for more information.
The only years silver was used in US nickels was 1942-1945, the coin is face value.
These coins are also frequently called Indian Head nickels; both names are about equally common. Please see the question "What is the value of a 1934 US nickel?" for more information.
Your nickel contains no silver. Only nickels made from 1942-1945 contain silver. See the related question below.
If you found it in change your nickel is only worth face value. US nickels made from 1866 to mid-1942 and from 1946 to the present are made of a copper-nickel alloy, not silver. In fact, no circulating US coins have contained any silver since 1969.
That's a silver war nickel, containing 35% silver, and it's worth at least $2.
Please check your bill again. There were no series letters on 1934 silver certificates, and no silver certificate series letters ever went as high as K. Please see the question "What is the value of a 1934 US 1 dollar silver certificate?" for more information.
The blue seal indicates your bill is a silver certificate. Please see the question "What is the value of a 1934 A US 5 dollar silver certificate?" for more information.
Copper-nickel, not silver. The only nickels that ever contained any silver were the famous "war nickels" made from 1942 to 1945, when silver replaced nickel metal because nickel was needed for the war effort.
The 1949 Jefferson nickel is still found in circulation, contains no silver and likely only face value.
The only US nickels to contain silver are those minted during WWII. A 1959 nickel in uncirculated condition might go for 25 cents.
That is known as a "war nickel" to save nickel for the war effort, the US government replaced some of the nickel in the nickel with silver. At the time of writing the silver content in them is around $1.70. The reason for the mintmark over the Monticello was that the idea was that people would know they contained silver.