# JEE Main Solved Physics Practice Paper 2017 - 2018 Set-III

In this article, Subject Experts of Physics bring to you solved practice paper of Physics for JEE Main entrance examination 2018. There are 30 questions in this paper and solutions of all the questions are explained in a detailed manner. It will help engineering aspirants to increase their speed and accuracy in the examination.

JEE Main Examination 2018

There are three subjects i.e., Physics, Chemistry and Mathematics in JEE Main entrance examination. All subjects are important to secure good marks in the examination. Engineering aspirants have already covered most of the syllabus for all three subjects.

Now, aspirants should focus on solving more and more practice papers to increase their speed and accuracy. It is very important to get familiar with the pattern of the examination before appearing for the final examination.

In this article, engineering aspirants who are going to appear for JEE Main entrance examination 2018 will find Solved Practice Paper of Physics based on the latest pattern and syllabus.

JEE Main Physics Syllabus: 2017 – 2018

1. This paper consists of 30 questions from easy to tough level.

2. It is prepared by experienced Subject Experts of Physics.

3. Questions have been taken from different topics like Gravitation, Electric Charges and Fields, Electrostatic Potential and Capacitance, Current Electricity, Light, Laws of Motion, Properties of Bulk Matter etc.

4. Detail solution for all the questions.

Few sample questions from the Practice Paper are given below:

Question

A speech signal of 3 kHz is used to modulate a carrier signal of frequency 1 MHz, using amplitude modulation. The frequencies of the side bands will be

(a) 1.003 MHz and 0.997 MHz

(b) 3001 kHz and 2997 kHz

(c) 1003 kHz and 1000 kHz

(d) 1 MHz and 0.997 MHz

Sol. (a)

Given, frequency of carrier signal is wc = 1 MHz

and frequency of speech signal = 3 kHz

= 3 × 10-3MHz

= 0.003 MHz

Now, we know that,

Frequencies of side bands = (wc ± wm)

= (1 ± 0.003)

= 1.003 MHz and 0,997 MHz

Question

Hole is

(a) An anti-particle of electron

(b) A vacancy created when an electron leaves a covalent bond

(c) Absence of free electrons

(d) An artificially created particle

Sol. (b)

The concept of hole describes the lack of an electron at a position where one could exist in an atom or atomic lattice. If an electron is excited into a higher state, it leaves a hole in its old state.

Question

An electron is projected with uniform velocity along the axis of a current carrying long solenoid. Which of the following is true?

(a) The electron will be accelerated along the axis

(b) The electron path will be circular about the axis

(c) The electron will experience a force at 45° to the axis and hence execute a helical path

(d) The electron will continue to move with uniform velocity along the axis of the solenoid

Sol. (d)

Magnetic Lorentz force electron is projected with uniform velocity along the axis of a current carrying long solenoid F = -evB sin180° = 0 (θ = 0°) as magnetic field and velocity are parallel. The electron will continue to move with uniform velocity along the axis of the solenoid.

Question

In a Young's double-slit experiment, the source is white light. One of the holes is covered by a red filter and another by a blue filter. In this case,

(a) There shall be alternate interference patterns of red and blue

(b) There shall be an interference pattern for red distinct from that for blue

(c) There shall be no interference fringes

(d) There shall be an interference pattern for red mixing with one for blue

Sol. (c)

For the interference pattern to be formed on the screen, the sources should be coherent and emits lights of same frequency and wavelength.

In a Young's double-slit experiment, when one of the holes is covered by a red filter and another by a blue filter. In this case due to Alteration only red and blue lights are present. In YDSE monochromatic light is used for the formation of fringes on the screen. Hence, in this case there shall be no interference fringes.

Conclusion:

This solved practice paper will help you to practice new set of questions from different topics like Electric Charges and Fields, Electrostatic Potential and Capacitance, Light, Laws of Motion, Properties of Bulk Matter. It will also help you to manage speed and accuracy in the examination.