The time taken by a train $35\text{ m}$ long, running at $90\text{ km/hr}$, in crossing an electric pole is:

Given:
Length of the train (Distance to be covered) = $35\text{ m}$
Speed of the train = $90\text{ km/hr}$

First, convert the speed from $\text{km/hr}$ to $\text{m/s}$:

$$\text{Speed}=90\times \frac{5}{18}=5\times 5=25\text{ m/s}$$

Now, calculate the time taken to cross the electric pole:

$$\text{Time}=\frac{\text{Distance}}{\text{Speed}}$$

$$\text{Time}=\frac{35}{25}=\frac{7}{5}=1.4\text{ seconds}$$