The wheels of a train, engine as well as bogies, are slightly tapered to
Show Hint
- Reduce friction
- Increase friction
- Facilitate braking
- Facilitate in taking turns
The Correct Option is D
Solution and Explanation
Top Questions on Mechanics
- The Hamiltonian for a one-dimensional system with mass \( m \), position \( q \), and momentum \( p \) is: \[ H(p, q) = \frac{p^2}{2m} + q^2 A(q) \] where \( A(q) \) is a real function of \( q \). If \[ m \frac{d^2 q}{dt^2} = -5q A(q), \] then \[ \frac{d A(q)}{d q} = n \frac{A(q)}{q}. \] The value of \( n \) (in integer) is:
- GATE PH - 2025
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- The energy of a free, relativistic particle of rest mass \( m \) moving along the \( x \)-axis in one dimension, is denoted by \( T \). When moving in a given potential \( V(x) \), its Hamiltonian is \( H = T + V(x) \). In the presence of this potential, its speed is \( v \), conjugate momentum \( p \), and the Lagrangian \( L \). Then, which of the following option(s) is/are correct?
- GATE PH - 2025
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A two-level quantum system has energy eigenvalues \( E_1 \) and \( E_2 \). A perturbing potential \( H' = \lambda \Delta \sigma_x \) is introduced, where \( \Delta \) is a constant having dimensions of energy, \( \lambda \) is a small dimensionless parameter, and \( \sigma_x = \begin{pmatrix} 0 & 1 \\ 1 & 0 \end{pmatrix} \).
The magnitudes of the first and the second order corrections to \( E_1 \) due to \( H' \), respectively, are:- GATE PH - 2025
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Consider a two-level system with energy states \( +\epsilon \) and \( -\epsilon \). The number of particles at \( +\epsilon \) level is \( N+ \) and the number of particles at \( -\epsilon \) level is \( N- \). The total energy of the system is \( E \) and the total number of particles is \( N = N+ + N- \). In the thermodynamic limit, the inverse of the absolute temperature of the system is:
(Given: \( \ln N! \approx N \ln N - N \))- GATE PH - 2025
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- A paramagnetic material containing paramagnetic ions with total angular momentum \( J = \frac{1}{2} \) is kept at absolute temperature \( T \). The ratio of the magnetic field required for 80% of the ions to be in the lowest energy state to that required for having 60% of the ions to be in the lowest energy state at the same temperature is:
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Questions Asked in AP PGECET exam
The rank of matrix \(\begin{bmatrix} k & -1 & 0 \\[0.3em] 0 & k & -1 \\[0.3em] -1 & 0 & k \end{bmatrix}\) is 2, for \( k = \)
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If \(A = \begin{bmatrix} 4 & 2 \\[0.3em] -3 & 3 \end{bmatrix}\), then \(A^{-1} =\)
- AP PGECET - 2024
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A two-port network is defined by the relation
\(\text{I}_1 = 5V_1 + 3V_2 \)
\(\text{I}_2 = 2V_1 - 7V_2 \)
The value of \( Z_{12} \) is:- AP PGECET - 2024
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An induction motor when started on load does not accelerate up to full speed but runs at \({\frac {1}{17}}\)th of the rated speed. The motor is said to be:
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A 0 to 30 V voltmeter has an error of \(\pm 2\%\) of FSD. What is the range of readings if the voltage is 30V?
- AP PGECET - 2024
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