Physics
2019 · Paper 1
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Complete GATE PH 2019 Paper 1 overview, original pages and practice · Timed previous-paper practice
Questions 64–65 of 65. Imported answers require review unless explicitly marked reviewed.
Question 54
Open questionPHNAT2 marksNeeds review
Two events, one on the earth and the other one on the Sun, occur simultaneously in the earth’s frame. The time difference between the two events as seen by an observer in a spaceship moving with velocity
in the earth’s frame along the line joining the earth to the Sun is
, where
is the speed of light. Given that light travels from the Sun to the earth in 8.3 minutes in the earth’s frame, the value of
in minutes (rounded off to two decimal places) is ______(Take the earth’s frame to be inertial and neglect the relative motion between the earth and the sun)
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Open questionPHNAT2 marksNeeds review
In a certain two-dimensional lattice, the energy dispersion of the electrons is
where
denotes the wave vector,
is the lattice constant and
is a constant in units of eV. In this lattice the effective mass tensor
of electrons calculated at the center of the Brillouin zone has the form
. The value of
(rounded off to three decimal places) is ______Log in to check the answer
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