*_🫰🏻SOME IMPORTANT MCQS_🫰🏻* *~Est Vesanus~* Q.1 When a helium atom loses an electron, it becomes: A) An alpha particle. B) A positive helium ion. C) Proton. D) A negative helium ion. Q.2 Beta ray emitted by a radioactive substance is: A) An electron which was existing outside the nucleus. B) An electron which was existing inside the nucleus. C) An electron emitted by the nucleus as a result of the decay of neutron inside the nucleus. D) A pulse of electromagnetic wave Q.3 An electric charge in uniform motion produces: A) An electric field. B) Both magnetic and electric fields. C) A magnetic field. D) Neither magnetic nor electric fields Q.4 What is emitted by a hot metal filament in a cathode ray tube? A) X-ray. B) Electron. C) Proton. d) Photon. Q.5 If the mass of the bob of a pendulum is doubled its time period is: A) Halved. B) Unchanged. C) Doubled. D) Increases four times. Q.6 The centre of Newton rings is dark due to: A) Polarization. B) Constructive interference. C) Destructive interference. D) Reflection Q.7 Which one is most stable element on the basis of binding energy? A) Sn. B) Kr. c ) Ba. D) Fe. Q.8 Resistance in RC circuit of time constant 2 seconds is 1000 Ohms. What is value of C in the circuit? A) 2 μ farad. B) 200 μ farad. C) 20 μ farad. D) 2000 μ farad Q.9 The Lenz’s law refers to induced __________ A) emf. B) Shear. C) Resistance. D) Currents. *Est Vesanus* Q.10 In which of the following, output is similar to NAND gate if input A=0 and input B=1. A) NOR. B) XOR C) XNOR. D) Both B and C. Q.11 For atomic hydrogen spectrum, which of the following series lies in visible region of electromagnetic spectrum? A) Lyman series B) Balmer series. C) Paschen series. D) Bohr series. Q.12 __________ are the particles that experience strong nuclear force. A) Electrons. B) Neutrinos. C) Muons. D) Neutrons. Q.13 The vertical velocity of ball thrown upward __________ with time. A) Decreases linearly. B) Doubles. C) Remains constant. D) Decreases parabolically. Q.14 The force required to bend the normally straight path of a particle into a circular path is called __________ force. A) Traveling. B) Centrifugal. C) Bending. D) Centripetal. Q.15 A disc at rest without slipping, rolls down a hill of height (3 x 9.8) m. What is its speed in m/sec when it reaches at the bottom? A) 11.4. C) 22.8. B) 19.6. D) 9.8. Q.16 Tuning of the radio is the best example of electrical __________ A) Resonance. B) Current. C) Resistance. D) None of these. Q.17 A standing wave pattern is formed when the length of string is an integral multiple of __________ wavelength. A) Triple. B) Half. C) Full. D) Double. Q.18 Which of the following lights travels the fastest in optical fibres? A)Visible light. B) Ultra-violet. C) Invisible infra-red. D) Ordinary light. Q.19 The algebraic sum of potential changes in a closed circuit is zero is Kirchhoff’s __________ rule. First. B) Third. C) Second. D) None of these. Q.20 In LED when an electron combines with a __________ during forward bias conduction, a photon of visible light is emitted. A) High voltage. B) Hole. C) Photon. D) Positron *Regards......Est Vesanus♥️*