Subhash Kumar: Your Educational Guide

Answer

Voltage Gain of a CE Amplifier is given by Av = β (RL / Rin)

                                                         Where             β = (ΔIc / ΔIb)

Now it is given that

Rin   = 100 Ω 

RL  = 4K Ω = 4000 Ω

ΔIb = 40µA = 40*10-6 A

ΔIc   = 2mA = 2*10-3 A

Hence, by putting these values we get Av = (ΔIc / ΔIb) *(RL/ Rin)

                                                                                = (2*10-3 /40*10-6)*(4000/100)

                                                                                =  50*40

                                                                                = 2000

Hence the correct option will be (D) 2000.

Answer

Centre of mass of the system is given by Xcm = (m1x1+ m2x2+ …+ mnxn)/ (m1+ m2+ …+ mn)

                                                   0(300)                    40(500)                  70(400)

 Here, 

m1 = 300g                    x1 =0 cm  (At origin)

m1 =500g                    x2 =40 cm

m1=400g                     x3 =70 cm

Hence by putting these values we get, Xcm = (0*300 + 40*500 + 70*400)/(300+500+400)

                                                                 = 48000/1200 =40 cm

Hence Correct Option will be (D) 40cm

Answer

Correct Option is (A) The inductances of a coil will increase under all the conditions except when more length for the same number of turns is provided.

Answer

The correct answer is (A) Inductance.

Answer

Ther correct answer is (C) cuts magnetic flux

Answer

Correct Answer is (A) Self Inductance