GPL - IES Question |

Branch

1.

For smooth and reliable operation of an amplifier using BJT, it is necessary that the circuit must be properly designed from the point of view of bias stabilization, because
1. reverse saturation current l_co increases with rise in temperature.
2. V_be decreases with rise in temperature.
3. h_fe or β changes with change of temperature and replacement of the transistor.
4. h_fe or β changes with change in collector supply voltage.
(a) 1,2 and 3
(b) 1,2 and 4
(c) 2,3 and 4
(d) 1, 2, 3 and 4

asked in Electronics Paper-1, 2011

View Comments [0 Reply]
2.

Intense magnetic field may be produced in a coil by using a
(a) normal metal with a large number of turns and sending a large current
(b) Type 1 superconductor with a large number of turns and sending a large current
(c) Type 2 superconductor with a large number of turns and sending a large current
(d) Type 2 superconductor with a large number of turns but limiting the current density below a critical value

asked in Electronics Paper-1, 2011

View Comments [0 Reply]
3.

The unit cell of a certain type of crystal is defined by three vectors a, b and c. The vectors are mutually perpendicular, but a ≠ b ≠ c. The crystal structure is
(a) triclinic
(b) tetragonal
(c) orthorhombic
(d) monoclinic

asked in Electronics Paper-1, 2011

View Comments [0 Reply]
4.

Biasing is used in transition amplifiers to
1. stabilize the operating point against temperature variations.
2. place the operating point in the linear region of the characteristics.
3. make α, β and l_co of the transistor independent of temperature variations.
4. reduce distortion and increase dynamic range.
(a) 1,2,3 and 4
(b) 1, 2 and 4
(c) 1,2 and 3
(d) 2, 3 and 4

asked in Electronics Paper-1, 2011

View Comments [0 Reply]
5.

The resistivity of a metal is a function of temperature because
(a) the electron density varies with temperature
(b) the electron gas density varies with temperature
(c) the lattices vibration increases with temperature
(d) collision of electrons increases as temperature increases

asked in Electronics Paper-1, 2011

View Comments [0 Reply]
6.

An intrinsic semiconductor has the following properties:
1. Its electron concentration equals its hole concentration.
2. Its carrier density increases with temperature.
3. Its conductivity decreases with temperature.
(a) 1, 2 and 3
(b) 2 and 3
(c) 1 and 3
(d) 1 and 2

asked in Electronics Paper-1, 2011

View Comments [0 Reply]

1778 1 2 3 ›› ... 297

Select an option to search: