PPF: Rs 1.2 lakh/y vs Rs 10K/m — which builds more?

The Public Provident Fund (PPF) is a government-backed small savings scheme, where investors can invest to create a tax-free corpus in the long term. The Finance Ministry reviews the PPF interest rate along with other small savings scheme rates every quarter. For the July-September quarter, the rate of interest in the PPF is 7.1% per annum. The scheme has a maturity period of 15 years. But which investment frequency can help you gather a larger PPF corpus in 15 years- Rs 1.2 lakh lump sum investment every year or Rs 10,000 per month?