List of top Geophysics Questions

A long coaxial cable carries current 'I' (current flows down the surface of inner cylinder of radius 'r1' and back along the outer cylinder of radius 'r2'). The magnetic energy stored in a section of length 'L' is

The magnetic polarization results in a bound current Jb
(A) which is associated with magnetization of the material.
(B) which involves spin and orbital motion of electrons.
(C) which is the result of linear motion of charge when electric polarization changes.
(D) which is given by \( \nabla \times \vec{M} \) (where \( \vec{M} \) is magnetization).
Choose the correct answer from the options given below:

Match List-I with List-II

\[ \begin{array}{|l|l|} \hline \textbf{List-I} & \textbf{List-II} \\ \hline (A) \; \text{Displacement current } (J_d) & (I) \; \frac{\epsilon_0}{2} \int E^2 d\tau \\ (B) \; \text{Poynting vector} & (II) \; \nabla \cdot \vec{E} = \frac{\rho}{\epsilon_0} \\ (C) \; \text{Energy stored in electric field } (\vec{E}) & (III) \; \frac{1}{\mu_0}(\vec{E} \times \vec{B}) \\ (D) \; \text{Gauss's Law} & (IV) \; \epsilon_0 \frac{\partial \vec{E}}{\partial t} \\ \hline \end{array} \]
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Which of the following orders in a double slit Fraunhofer diffraction pattern will be missing if the slit width is 0.12 mm and slits are 0.6 mm apart?

Match List-I with List-II

\[ \begin{array}{|l|l|} \hline \textbf{List-I} & \textbf{List-II} \\ \hline (A) \; \text{Force} & (I) \; \text{Torque} \\ (B) \; \text{Distance covered} & (II) \; \text{Angle described} \\ (C) \; \text{Mass} & (III) \; \text{Moment of inertia} \\ (D) \; \text{Linear velocity} & (IV) \; \text{Angular velocity} \\ \hline \end{array} \]
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If J, E and I are the angular momentum, kinetic energy of rotation and moment of inertia respectively, then which of following is incorrect?

Work done in compressing adiabatically 1g of air, initially at NTP to one fourth of its original volume is: (take density of air = 0.0001465 g/cm³ and \(\gamma\) = 1.5)

Two tuning forks produce 6 beats per second when sounded together. One of the fork is in unison with 1.5 m length of wire and the other with 2.0 m length of wire. The frequencies of forks are:

Change of entropy of a perfect gas for isochoric process is

The ratio of adiabatic to the isobaric coefficient of expansion is

A moving particle has coordinates (5t + 3, 6t, 5)m in frame S at any time 't'. The frame s' is moving with velocity (3\(\hat{i}\)+4\(\hat{j}\))m/s with respect to the frame S. Velocity of particle in frame s' is:

Which of following is correct form of first TdS equation ?

Match List-I with List-II

\[ \begin{array}{|l|l|} \hline \textbf{List-I} & \textbf{List-II} \\ \hline (A) \; \text{Classius Clapeyron equation} & (I) \; PV^\gamma = \text{constant} \\ (B) \; \text{Gibbs Function} & (II) \; U + PV \\ (C) \; \text{Enthalpy} & (III) \; U - TS + PV \\ (D) \; \text{Adiabatic change in Perfect Gas} & (IV) \; \dfrac{dP}{dT} = \dfrac{L}{T (V_2 - V_1)} \\ \hline \end{array} \]
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A zone plate

The energy radiated per minute from the filament of an incandescent lamp at 2000 K, surface area \( 4 \times 10^{-5} \) m² and relative emittance is 0.85, will be (Given Stefan's constant \( \sigma = 5.7 \times 10^{-8} \) Jm⁻²s⁻¹K⁻⁴)

Two satellites A and B of mass 'M' are orbiting the earth in circular orbits at altitudes 2R and 5R respectively, where R is the radius of the earth. The ratio of kinetic energies of satellite A and B will be

The Rayleigh Jean's Law,
(A) agrees well with experimental results at low frequencies.
(B) agrees well with experimental results at longer. wavelengths.
(C) shows ultra-violet catastrophe at higher frequencies.
(D) agrees well with experimental results at higher frequencies.
Choose the correct answer from the options given below:

Which of the following is/are correct about conservative and non-conservative forces?
(A) For conservative and non-conservative forces conservation of energy holds good.
(B) Friction is a conservative force.
(C) The work done by a conservative force in a closed path is zero.
(D) Friction is a non-conservative force.
Choose the correct answer from the options given below:

A power gain of 100 in decibel (db) is:

In common emitter connection, the collector leakage current in a transistor is 300\(\mu\)A. The leakage current in the transistor in common base arrangement will be (Given \(\beta\) = 130):

Match List-I with List-II

\[ \begin{array}{|l|l|} \hline \textbf{List-I} & \textbf{List-II} \\ \hline (A) \; \text{Zener diode} & (I) \; \text{Negative resistance region} \\ (B) \; \text{Tunnel diode} & (II) \; \text{Voltage regulator} \\ (C) \; \text{Rectifier} & (III) \; \text{Pulsating d.c.} \\ (D) \; \text{Light emitting diode} & (IV) \; \text{Gallium Arsenide phosphide (GaAsP)} \\ \hline \end{array} \]
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An a. c. supply of 220V is applied to a half wave rectifier through a transformer of turn ratio 20:1. In this circuit the peak inverse voltage is:

Given the following staff readings at two levels, determine the Reduced Level (RL) of B. 

Given: - RL of A = 150 m - Find RL of B

Given the bearing N30°W, determine the corresponding Whole Circle Bearing (WCB). \

 Given: - Bearing = N30°W - Find WCB