# Electronics and Communication Engineering - Exam Questions Papers

46.
Consider the following statements:
In a microstrip line
1. Wavelength , where eff is the effective dielectric constant and 1 is the free space wavelength.
2. Electromagnetic fields exist partly in the air above the dielectric substrate and partly within the substrate itself.
3. The effective dielectric constant is greater than the dielectric constant of the air.
4. Conductor losses increase with decreasing characteristic impedance.
Which of the above statements is/are correct?
1, 2 and 3
1 and 2 only
2, 3 and 4
2, 3 and 4
Explanation:
No answer description is available. Let's discuss.

47.
In the circuit below, if diodes and the moving coil millimeter are assumed to be ideal if mA reading is , find Vm.
1 mV
0.1 V
0.1 mV
1 V
Explanation:

Now,

Im = pIDC = 0.1 mA

Vm = Im x R = 0.1 mA x 10 K

Vm = 1 Volt.

48.
What current does represent in pn junction diode? (where the symbols have their usual meaning)
Forward current
Diffusion current
Drift current
Reverse saturation current
Explanation:
No answer description is available. Let's discuss.

49.
What happens when a paramagnetic material is heated above Curie temperature?
It becomes diamagnetic
It becomes nonmagnetic
It becomes ferromagnetic
It becomes anti-ferromagnetic