STAG3104

Rocks and minerals exhibit two types of magnetism. What are these types?

• Induced magnetism and remnant magnetism

• Magnetic susceptibility and ferromagnetism

• Anti-ferro magnetism and ferrimagnetism

• Diamagnetism and paramagnetism

Geophysical methods can be classified into passive and active methods. What are the passive methods?

I. Self-potential

II. Induced polarization

III. Seismic refraction

IV. Magnetic

• I an II

• I, II, and IV

• I and IV

• II and IV

Which factors below affect the variation of the magnetic field?

I. Secular variation

II. Night variation

III. Diurnal variation

IV. Daylight variation

• I and II

• IV and III

• II and IV

• I and III

Based on the types of minerals listed below, which one has the highest magnetic susceptibility?

• Hematite

• Limonite

• Magnetite

• Pyrite

What is the physical parameter measured in induced polarization?

• Conductivity

• Resistivity

• Chargeability

• Electricity

Polarization is induced in ground by two mechanisms during current flow. Over voltage effect occurs by decay in polarization as charges migrate away by

• Grain polarization and capillary polarization

• Membrane polarization and grain polarization

• Electrode polarization and Cathode polarization

• Anode polarization and cathode polarization

When the current is switched off, the ions at the grain diffuse away into the fluid, gradually reducing the potential to zero within a finite time. This phenomenon is referred to as?

• Membrane polarization

• Overvoltage effect

• Conductivity

• Electrode polarisation

The measurement of IP (Induced Polarization) can be classified into two types. What are these types of IP measurement?

I. Time-domain IP

II. Wavelength-domain IP

III. Frequency-domain IP

IV. Lamda-domain IP

• I and III

• II and IV

• I and III

• III and IV

Gravity method measures variations in the Earth’s gravitational field caused by differences in …………………….. of subsurface rocks

A surface where the gravitational field has an equal value throughout (equipotential surface) is known as what?

• Earth’s surface

• Geoid

• Datum

• Ellipsoid