Which of the following is an invalid state in an 8-4-2-1 Binary Coded Decimal Counter?

(a) 1 0 0 0

(b) 1 0 0 1

(c) 0 0 1 1

(d) 1 1 0 0

Which of the following is an invalid state in an 8-4-2-1 Binary Coded Decimal Counter?

(a) 1 0 0 0

(b) 1 0 0 1

(c) 0 0 1 1

(d) 1 1 0 0

Sorry total less than 9 not 8.in option a 8<9,b:9=9,c:3<9,d:12>9.only option C satisfy the condition (total <9)

@Jp123 im little bit confused because 8<9 also 3<9 so why the answer is option is C.

I think D part should be the correct option.

Hai good evening.Decimal number(1100)is equal to 12(in bcd).but in bcd we can represent up-to 9 in decimal(other than we can not represent. In case we present we follow another method). So those digital number can represent in bcd that digital number total in bcd should satisfy condition (<9).in the given question these condition satisfy the option A, C.(we can tick either A or c they given mark) and thank you Harsh for asking question.

hello @jp123 here they have asked invalid state in bcd counter so option d is correct naa

because here 8<9 , 9=9

3<9 and 12>9 so d is correct answer

Because it is invalidâ€‹:blush: