1024, 64, 8, 2, 1, 1, 4
In each of these questions a number series is given. In each series only one number is wrong. Find out the wrong number.

The correct answer is 4.

To find the wrong number in the series, let us analyze the pattern of operations between consecutive terms:
First term = 1024
Second term = 64, which is obtained by dividing 1024 by 16
Third term = 8, which is obtained by dividing 64 by 8
Fourth term = 2, which is obtained by dividing 8 by 4
Fifth term = 1, which is obtained by dividing 2 by 2
Sixth term = 1, which is obtained by dividing 1 by 1

Notice the pattern of the divisors: 16, 8, 4, 2, 1. These divisors are decreasing powers of 2:
$2^4=16$
$2^3=8$
$2^2=4$
$2^1=2$
$2^0=1$

Following this logic, the next divisor in the sequence must be:
$2^{-1}=0.5$

Applying this divisor to the sixth term to find the seventh term:
$1/0.5=2$

Since the seventh term in the given series is 4 instead of 2, the number 4 is wrong.