Q.

A wheel initially at rest is subjected to a uniform angular acceleration about its axis. In the first 2 s it rotates through an angle θ1 and in the next 2 s it rotates through an angle θ2. The ratio θ2θ1 is ______.               [2026]

1 6  
2 3  
3 4  
4 13  

Ans.

(2)

Let α be angular acceleration

In first 2 sec, θ1=12α(2)2=2α

θ'=12(α)(4)2=8α

θ2=θ'-θ1=8α-2α=6α

⇒θ2θ1=6α2α=3