Semiconductor Electronic: Material, Devices And Simple Circuits — Physics STD 12 Science — Question

As the switch S is closed in the circuit shown in figure, current passed through it is

(a) 4.5 A

(b) 6.0 A

(c) 3.0 A

(d) Zero

The wires 1 and 2

A triode is operated in the linear region of its characteristics. If the plate voltage is slightly increased, the dynamic plate resistance will:

A magnifying glass is to be used at the fixed object distance of 1 inch. If it is to produce on erect image 5 items magnified, its focal length should be :

In a fission reaction , the binding energy per nucleon of X and Y is 8.5 MeV whereas of  is 7.6 MeV. The total energy liberated will be about

(a) 200 KeV

(b) 2 MeV

(c) 200 MeV

(d) 2000 MeV

Taking Rydberg’s constant  first and second wavelength of Balmer series in hydrogen spectrum is

(a) 2000 Å, 3000 Å

(b) 1575 Å, 2960 Å

(c) 6529 Å, 4280 Å

(d) 6552 Å, 4863 Å

The ripple factor in a half wave rectifier is

(a) 1.21

(b) 0.48

(c) 0.6

(d) None of these

In a transistor in CE configuration, the ratio of power gain to voltage gain is

(a) a

(b) b / a

(c) ba

(d) b

The coil of the moving coil galvanometer is wound over an aluminium frame: