A given solar cell has the following specifications:
Open-circuit voltage, Voc: 0.7 V
Short-circuit current, Isc: 3 A
Voltage at maximum power, Vmp: 0.5 V
Current at maximum power, Imp : 2.65 A
Calculate the fill factor.

Where,
Pmp is maximum power in watt
Vmp maximum voltage at maximum power in volt
Imp is maximum current at maximum power in ampere
Voc open circuit voltage in volt
Isc is short circuit current in ampere

Fill Factor = Pmp/(Vosc*Isc) = (Vmp*Imp)/(Voc*Isc)
= (2.65*0.5)/(0.7*3)
= 0.63

In a typical DC micro grid, hybrid storage system is a combination of

Hybrid storage system is a combination of microturbines, fuel cells, photovoltaics (PV), Lead acid battery and ultra or super capacitors etc.

A circular loop has its radius increasing at a rate of 2 m/s. The loop is placed perpendicular to a constant magnetic field of 0.1 Wb/m². When the radius of the loop is 2 m, the emf induced in the loop will be

emf = dΨ/dt = change of flux linkage
emf = dф/dt
emf = d(B*Area)/dt
emf = B*d(area)/dt
emf = B*d(πr²)/dt
emf = Bπ*2r*dr/dt
emf = Bπ*2r*change of radius per unit time
emf = 0.1*π*2*2
emf = 4π

A three-phase, 4-pole, 50 Hz induction motor runs at 1425 rpm. Find out the percentage slip of the induction motor.

Slip, s = (Ns - Nr)/Ns
Ns = 120f/P
Ns = 1500 rpm

s = (1500 - 1425)/1500
s = 0.05
%s = 5%

Which of the following is linux operating system?

Recently, which country has withdrawn the 'Generalized System of Preferences' with India?