If $1.00029=l(1+2.9\times 10^{-5}\times 10)$, the value of $l$ is

Let us simplify the expression inside the bracket:
$$1+2.9\times 10^{-5}\times 10=1+2.9\times 10^{-4}$$

$$2.9\times 10^{-4}=0.00029$$

So, the bracketed term becomes:

$$1+0.00029=1.00029$$

Now, substitute this back into the equation:

$$1.00029=l\times 1.00029$$

$$l=\frac{1.00029}{1.00029}=1$$