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Chapter 14 Semiconductors 1. Choose the correct option. Question 1.Electric conduction through a semiconductor is due to:(A) Electrons(B) holes(C) none of these(D) both electrons and holesAnswer:(D) both electrons and holes Question 2.The energy levels of holes are:(A) in the valence band(B) in the conduction band(C) in the band gap but close to valence band(D) in … Read more

Chapter 13 Electromagnetic Waves and Communication System 1. Choose the correct option. Question 1.The EM wave emitted by the Sun and responsible for heating the Earth’s atmosphere due to the greenhouse effect is(A) Infra-red radiation(B) X-ray(C) Microwave(D) Visible lightAnswer:(A) Infra-red radiation Question 2.Earth’s atmosphere is richest in(A) UV(B) IR(C) X-ray(D) MicrowavesAnswer:(B) IR Question 3.How does … Read more

1. Choose the correct option. Question 1.Let r be the distance of a point on the axis of a bar magnet from its center. The magnetic field at r is always proportional to Question 2.Magnetic meridian is the plane(A) perpendicular to the magnetic axis of Earth(B) perpendicular to geographic axis of Earth(C) passing through the … Read more

1. Choose the correct Alternative. Question 1.You are given four bulbs of 25 W, 40 W, 60 W, and 100 W of power, all operating at 230 V. Which of them has the lowest resistance?(A) 25 W(B) 40 W(C) 60 W(D) 100 WAnswer:(D) 100 W Question 2.Which of the following is an ohmic conductor?(A) transistor(B) … Read more

Chapter 10 Electrostatics 1. Choose the correct option. Question 1.A positively charged glass rod is brought close to a metallic rod isolated from the ground. The charge on the side of the metallic rod away from the glass rod will be(A) same as that on the glass rod and equal in quantity(B) opposite to that … Read more

1. Multiple Choise Questions Question 1.As per the recent understanding, light consists of(A) rays(B) waves(C) corpuscles(D) photons obeying the rules of wavesAnswer:(D) photons obeying the rules of waves Question 2.Consider the optically denser lenses P, Q, R, and S drawn below. According to the Cartesian sign convention which of these have a positive focal length? … Read more

Chapter 8 Sound 1. Choose the correct alternatives Question 1.A sound carried by the air from a sitar to a listener is a wave of the following type.(A) Longitudinal stationary(B)Transverse progressive(C) Transverse stationery(D) Longitudinal progressiveAnswer:(D) Longitudinal progressive Question 2.When sound waves travel from air to water, which of these remains constant?(A) Velocity(B) Frequency(C) Wavelength(D) All … Read more

Chapter 6 Mechanical Properties of Solids 1. Choose the correct answer: Question 1.Change in dimensions is known as …………..(A) deformation(B) formation(C) contraction(D) strain.Answer:(A) deformation Question 2.The point on stress-strain curve at which strain begins to increase even without increase in stress is called…………(A) elastic point(B) yield point(C) breaking point(D) neck pointAnswer:(B) yield point Question 3.Strain … Read more

1. Choose the correct option. Question 1.The value of acceleration due to gravity is maximum at(A) the equator of the Earth(B) the centre of the Earth.(C) the pole of the Earth.(D) slightly above the surface of the Earth.Answer:(C) the pole of the Earth. Question 2.The weight of a particle at the centre of the Earth … Read more

Chapter 4 Laws of Motion 1. Choose the correct answer. Question 1.Consider the following pair of forces of equal magnitude and opposite directions:(P) Gravitational forces are exerted on each other by two-point masses separated by a distance.(Q) Couple of forces are used to rotate a water tap.(R) Gravitational force and normal force are experienced by … Read more