General Knowledge Questions

Because the refractive index of glass is highest, light travels slowly in Glass. 

We know that the speed of light depends on the refraction index. The higher the index of refraction is, the slower the speed of light is.

R.I of air and vacuum = 0 (air is a teeny bit more but can be taken as 0)
R.I of water = 1.33
R.I of glass = 1.4.

Hence, Light travels slowest in Glass.

India’s first-ever Rural LED Street Lighting Project will be implemented by the Government of India (GoI) in Andhra Pradesh (AP). The Energy Efficiency Services Limited (EESL) under the Ministry of Power will retrofit10 lakh conventional street lights with LED lights in Gram Panchayats of 7 districts in AP. This is the first project for rural LED street lighting in the country under the GoI’s Street Lighting National Project (SLNP). In the first phase, the replacement will be undertaken in gram panchayats of the districts of Guntur, Prakasham, Nellore, Kurnool, Kadapa, Ananthapur and Chittoor. This replacement drive in rural areas will help the gram panchayats to cumulatively save approximately 147 million units of electricity annually and lead to reduction of 12 crore tonnes of CO2. The entire upfront capital cost of this project is being funded by French Development Agency Agence Française de Développement (AFD).

Entropy is a measure of disorder . It will be maximum in gases followed by liquids and least in solids.

Hence, here the gas is only hydrogen and it has the highest entropy.

Mixtures are combination of two or more substances physically which can be separated in to the original.

Matter can be breakdown into two categories. 

1) Pure substances 

2) Mixtures

Here in the given options, options A, B, C are pure substances as they are indicated as S & L in brackets. Option D) is an aqueous solution, that can be dissolved in water.

DRDO stands for The Defence Research and Development Organisation.

The Defence Research and Development Organisation (DRDO) is an agency of the Republic of India, charged with the military's research and development, headquartered in New Delhi, India.

DPI [Dots Per Inch] is a measurement of output quality of printer resolution. It represents number of ink dots the printer can place in an area of one square inch. The lesser the DPI the less sharper the image and vice versa.

Therefore, a printer that may have 400 DPI, a printer that can print 400 x 400 per square inch or 1,60,000 dots per inch.