Physics
2018 · Paper 1
Take it one question at a time. Try an answer, then check your understanding.
Complete GATE PH 2018 Paper 1 overview, original pages and practice · Timed previous-paper practice
Questions 31–33 of 65. Imported answers require review unless explicitly marked reviewed.
Question 21
Open questionPHNAT1 markNeeds review
An infinitely long straight wire is carrying a steady current I. The ratio of magnetic energy density at distance
to that at
(= 2
) from the wire is ________.Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 22
Open questionPHNAT1 markNeeds review
A light beam of intensity
is falling normally on a surface. The surface absorbs 20% of the intensity and the rest is reflected. The radiation pressure on the surface is given by
, where X is ________ (up to one decimal place). Here c is the speed of light.Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 23
Open questionPHNAT1 markNeeds review
The number of independent components of a general electromagnetic field tensor is ________.
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