Answer:
1/9 E0
Step-by-step explanation:
The computation is shown below:
As we know that
![E_0 = K (Q)/(r2)](https://img.qammunity.org/2021/formulas/physics/college/5u4yhyvsczwjanftpyvcri285nietu6nsb.png)
where,
E = Electric field strength
k = Coulomb's constant
Q = charge on the sphere
r = distance from the center of the sphere
It is given that
The radius of the larger sphere is three times larger than that of the smaller sphere i.e
![R'=3R](https://img.qammunity.org/2021/formulas/physics/college/zq385eofy0lw0hbyxp1m2idy52bg5nig13.png)
![E'=k(Q)/(R'^2)](https://img.qammunity.org/2021/formulas/physics/college/33u10pegjkb2unwzp52v8t87oh64zcu6zb.png)
![=k(Q)/((3R)^2)](https://img.qammunity.org/2021/formulas/physics/college/4tnme1v045owd4uwwkpho51hafu3i7ui5t.png)
![=(1)/(9)(k(Q)/(R^2))](https://img.qammunity.org/2021/formulas/physics/college/yg29myui0ldx7qoniwaqrccarwh8l19mt7.png)
![=(E_0)/(9)](https://img.qammunity.org/2021/formulas/physics/college/cx2yb8zraba6jwphr9jaoje3kbw3ylaa6b.png)
hence, the last option is correct