**Solution:**

To find the effective rate of interest for one year corresponding to a nominal interest rate of 7% per annum convertible quarterly, we can use the formula for the effective interest rate:

Effective interest rate = (1 + (nominal interest rate / number of periods)) ^ number of periods - 1

In this case, the nominal interest rate is 7% per annum and it is convertible quarterly. Therefore, the number of periods is 4 (since there are 4 quarters in a year).

**Calculating the effective interest rate:**

Step 1: Convert the nominal interest rate to a quarterly rate
Nominal interest rate per quarter = (7% per annum) / 4 quarters
Nominal interest rate per quarter = 1.75%

Step 2: Calculate the effective interest rate using the formula
Effective interest rate = (1 + (1.75% / 4))^4 - 1

Step 3: Simplify the calculation
Effective interest rate = (1 + 0.0175)^4 - 1
Effective interest rate = (1.0175)^4 - 1
Effective interest rate = 1.0714 - 1
Effective interest rate = 0.0714

Step 4: Convert the effective interest rate to a percentage
Effective interest rate = 0.0714 * 100%
Effective interest rate = 7.14%

Therefore, the effective rate of interest for one year corresponding to a nominal interest rate of 7% per annum convertible quarterly is 7.14%.

Since none of the given options (Rs240, Rs200, Rs220, Rs210) match the calculated effective interest rate of 7.14%, none of the options is correct.