In Concentrating Photovoltaics (CPV), a large area of sunlight is focused onto the solar cell with the help of an optical device. By concentrating sunlight onto a small area, this technology has three competitive advantages: Requires less photovoltaic material to capture the same sunlight as non-concentrating pv. It makes the use of high-efficiency but expensive multi-junction cells economically viable due […]
A solar cell, or photovoltaic cell, is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon, solar cells are described as being photovoltaic, irrespective of whether the source is sunlight or an artificial light, a large majority of solar cells are made from silicon,
The sun produces an unbelievable amount of energy that reaches the earth. The amount of energy that is absorbed by the earth in one hour is more energy than mankind uses in one year. Solar Energy Systems The total amount of solar energy reaching the earth in one year is huge – twice as much
1. Which one of the following is correct ? (a) The effect of field current on main flux of a synchronous machine is called armature reaction (b) The effect of air gap flux on armature current of a synchronous machine is called armature reaction (c) The effect of armature current on main flux of a
1. The voltage wave v = Vm sin (wt – 15°) volts is applied across an AC circuit. If the current leads the voltage by 10° and the maximum value of currents is Im, then the equation of current is (a) i = Im sin (wt + 5°) amps (b) i = Im sin (wt
1. If in an R-L-C series circuit the current lags the applied voltage by 60° then (a) XL – XC = R/√3 (b) XL – XC = √3R (c) XL = XC = R (d) XL – XC = R 2. A lossy capacitor with loss angle of 0.01 radian, draws a current of 0.5
1. The value of voltage across the diode in figure given below is (a) Zero volt (b) 4 V (c) 8 V (d) Depends upon the value of R 2. The temperature co-efficient of an intrinsic semiconductor is (a) Zero (b) Positive (c) Negative (d) Like that of metals 3. A 4-pole, 1200 rpm DC
For rotary AC motors, asynchronous (induction) motors are more common than synchronous motors. But when it comes to linear motion, linear synchronous motors, abbreviated LSMs, are more common. The vast majority of LSMs I’ve seen have permanent magnets, so this article focuses exclusively on permanent magnet LSMs. Structure of Linear Synchronous Motors In general, linear
Linear motors move in a straight line with linear force and speed. Linear motion is needed in many types of systems, but linear motors aren’t commonly used by makers or professional engineers. That’s because these motors aren’t well-understood, there aren’t many manufacturers, and they’re expensive. For these reasons, designers frequently obtain linear motion by connecting
1. The value of current I flowing in the 1 ohm resistor in the circuit shown in the figure below will be (a) 10A (b) 6A (c) 5A (d) zero 2. In the figure shown below, if we connect a source of 2V, with internal resistance of 1 ohm at AA’ with positive terminal at