For  a common emitter configuration if α and β  have their  usual meaning the incorrect relationship between α and β is

A) $\frac{1}{\alpha}=\frac{1}{\beta}+1$

B) $\alpha =\frac{\beta}{1-\beta}$

C) $\alpha =\frac{\beta}{1+\beta}$

D) $\alpha =\frac{\beta^{2}}{1+\beta^{2}}$


Identify the semiconductor devices whose characteristics are as given below, in the order (a),(b), (c), (d)


A) Simple diode, Zener diode, Solar cell, Light dependent resistance

B) Zenar diode, Simple diode, Light dependent resistance, Solar cell

C) Solar cell, Light dependent resistance , Zenar diode, Simple diode

D) Zener diode ,Solar cell, Simple diode, Light dependent resistance


In an experiment for determination of the refractive index of a glass of a prism by i-δ plot, ut was found that a ray incident at an angle 35° suffers a deviation of 40° and that it emerges at an angle 790, In that case, which of the following is closest to the maximum possible value of the refractive index?

A) 1.5

B) 1.6

C) 1.7

D) 1.8


A galvanometer having a coil resistance of 100 Ω gives a full-scale deflection when a current of 1 mA is passed through it. The value of the resistance which can convert this galvanometer into ammeter giving a full-scale deflection for a current of 10 A is 

A) $0.01 \Omega$

B) $2 \Omega$

C) $0.1 \Omega$

D) $3 \Omega$


A pipe open at both ensa has a fundamental frequency f in air. The pipe is dipped vertically in the water, so that half of it is in water, The fundamental frequency of the air column is now

A) $\frac{f}{2}$

B) $\frac{3f}{4}$

C) $2f$

D) $f$