Practice Questions

Q2. The initial speed of a bullet fired from a rifle is 630 m/s. The rifle is fired at the centre of a target 700 m away at the same level as the target. How far above the centre of the target ? (1) 1.0 m (2) 4.2 m (3) 6.1 m (4) 9.8 m

Q3. A body of mass 5 kg under the action of constant force →F = Fx^i + Fy^j has velocity at t = 0 s as →v = (6^i −2^jm/s) and at t = 10 s as →v = +6^jm/s. The force →F is: (1) (−3^i + 4^j)N (2) (−35^i + 45 ^j)N (3) (3^i −4^j)N (4) ( 5^i3 −45^j)N

Q4. When a rubber-band is stretched by a distance x, it exerts a restoring force of magnitude F = ax + bx2 where a and b are constants. The work done in stretching the unstretched rubber-band by L is : (1) aL2 + bL3 (2) 12 (aL2 + bL3) bL3 bL3 (3) aL2 (4) + 2 + 3 2 1 ( aL22 3 )

Q6. Match List ‐I (Event) with List ‐ II (Order of the time interval for the happening of the event) and select the correct option from the options given below the lists. List-I List-II (a) The rotation period of earth (i) 105 s (b) Revolution period of earth (ii) 107 s (c) Period of a light wave (iii) 10−15 s (d) Period of a sound wave (iv) 10−3 s (1) (a)‐(i), (b)‐(ii), (c)‐(iii), (d)‐(iv) (2) (a)‐(ii), (b)‐(i), (c)‐(iii), (d)‐(iv) (3) (a)‐(i), (b)‐(ii), (c)‐(iv), (d)‐(iii) (4) (a)‐(ii), (b)‐(i), (c)‐(iv), (d)‐(iii) + N kg−1 . The change in the gravitational potential

Q7. In materials like aluminium and copper, the correct order of magnitude of various elastic modulii is : (1) Young's modulii < shear modulii < bulk modulii (2) Bulk modulii < shear modulii < Young's modulii (3) Shear modulii < Young's modulii < bulk modulii (4) Bulk modulii < Young's modulii < shear modulii

Q7. The bulk moduli of ethanol, mercury and water are given as 0.9, 25 and 2.2 respectively in units of 109Nm−2 . For a given value of pressure, the fractional compression in volume is ΔV . Which of the following statements V about ΔVV for these three liquids is correct ? (1) Ethanol > Water > Mercury (2) Water > Ethanol > Mercury (3) Mercury > Ethanol > Water (4) Ethanol > Mercury > Water

Q14.Which of the following expressions corresponds to simple harmonic motion along a straight line, where x is the displacement and a, b, c are positive constants? (1) a + bx −cx2 (2) bx2 (3) a −bx + cx2 (4) −bx

Q17.A parallel plate capacitor is made of two circular plates separated by a distance of 5 mm and with a dielectric of dielectric constant 2.2 between them. When the electric field in the dielectric is 3 × 104 V/m , the charge density of the positive plate will be close to : (1) 6 × 10−7 C/m2 (2) 3 × 10−7 C/m2 (3) 3 × 104 C/m2 (4) 6 × 104 C/m2

Q17.Three capacitances, each of 3 μF, are provided. These cannot be combined to provide the resultant capacitance of : (1) 2 μF (2) 6 μF (3) 1.5 μF (4) 1 μF

Q19.An example of a perfect diamagnet is a superconductor. This implies that when a superconductor is put in a magnetic field of intensity B, the magnetic field Bs inside the superconductor will be such that (1) Bs = B. (2) Bs = 0. (3) Bs < B but Bs ≠0. (4) Bs = –B

Q20.Three identical bars A, B and C are made of different magnetic materials. When kept in a uniform magnetic field, the field lines around them look as follows: Make the correspondence of these bars with their material being diamagnetic ( D), ferromagnetic (F) and paramagnetic (P) : (1) A ↔D, B ↔P, C ↔F (2) A ↔F, B ↔D, C ↔P (3) A ↔P, B ↔F, C ↔D (4) A ↔F, B ↔P, C ↔D JEE Main 2014 (11 Apr Online) JEE Main Previous Year Paper

Q22.If microwaves, X‐ rays, infrared, gamma rays, ultraviolet, radio waves and visible parts of the electromagnetic spectrum are denoted respectively by M , X , I , G , U , R and V the following is the arrangement in ascending order of the wavelength (1) I , M , R, U , V , X and G (2) R, M , I , V , U , X and G (3) M , R, V , X , U , G and I (4) G , X , U , V , I , M and R

Q22.A coil of circular cross-section having 1000 turns and 4 cm2 face area is placed with its axis parallel to a magnetic field which decreases by 10−2 Wb m−2 in 0.01 s. The e.m.f. induced in the coil is: (1) 400mV (2) 200mV (3) 4mV (4) 0.4mV

Q22.During the propagation of electromagnetic wave in a particular medium :- (1) Electric energy density is double of the magnetic (2) Electric energy density is half of the magnetic energy density energy density (3) Electric energy density is equal to the magnetic (4) Both electric and magnetic energy densities are energy density zero

Q23.Match List - I (Electromagnetic wave type) with List - II (Its association/application) and select the correct option from the choices given below the lists : JEE Main 2014 (06 Apr) JEE Main Previous Year Paper List - I List - II (a) Infrared waves (i) To treat muscular strain (b) Radio waves (ii) For broadcasting (c) X - rays (iii) To detect fracture of bones (d) Ultraviolet rays (iv) Absorbed by the ozone layer of the atmosphere (1) (a) (b) (c) (d) (2) (a) (b) (c) (d) (iv) (iii) (ii) (i) (i) (ii) (iv) (iii) (3) (a) (b) (c) (d) (4) (a) (b) (c) (d) (iii) (ii) (i) (iv) (i) (ii) (iii) (iv)

Q23.An electromagnetic wave of frequency 1 × 1014 hertz is propagating along z-axis. The amplitude of electric field is 4 V/m. If ε0 = 8.8 × 10−12C2/N−m2 , then average energy density of electric field will be: (1) 35.2 × 10−10 J/m3 (2) 35.2 × 10−11 J/m3 (3) 35.2 × 10−12 J/m3 (4) 35.2 × 10−13 J/m3

Q26.For which of the following particles will it be most difficult to experimentally verify the de-Broglie relationship? (1) An electron (2) An α-particle (3) A dust particle (4) A proton

Q26.Two monochromatic light beams of intensity 16 and 9 units are interfering. The ratio of intensities of bright and dark parts of the resultant pattern is: (1) 16 (2) 4 9 3 (3) 7 (4) 49 1 1

Q26.Match List ‐I (Experiment performed) with List ‐ II (Phenomena discovered/associated)and select the correct option from the options given below the lists List-I List-II (a) Davisson and Germer experiment (i) Wave nature of electrons (b) Millikan's oil drop experiment (ii) Charge of an electron (c) Rutherford experiment (iii) Quantisation of energy levels (d) Franck-Hertz experiment (iv) Existence of the nucleus (1) (a)‐(iii), (b)‐(iv), (c)‐(i), (d)‐(ii) (2) (a)‐(i), (b)‐(ii), (c)‐(iv), (d)‐(iii) (3) (a)‐(iv), (b)‐(iii), (c)‐(ii), (d)‐(i) (4) (a)‐(i), (b)‐(ii), (c)‐(iii), (d)‐(iv)

Q28.Match the List-I (Phenomenon associated with electromagnetic radiation) with List-II (Part of electromagnetic spectrum) and select the correct code from the choices given below this lists: (1) (I)-(A), (II)-(B), (III)-(B),,(IV)-(C) (2) (I)-(A), (II)-(B), (III)-(C), (IV)-(C) (3) (I)-(D), (II)-(C), (III)-(A), (IV)-(B) (4) (I)-(B), (II)-(A), (III)-(D), (IV)-(A)

Q28.For LED's to emit light in visible region of electromagnetic light, it should have energy band gap in the range of: (1) 0.1eV to 0.4eV (2) 0.5eV to 0.8eV (3) 0.9eV to 1.6eV (4) 1.7eV to 3.0eV

Q29.The forward biased diode connection is : (1) (2) (3) (4)

Q29.Identify the gate and match A, B, Y in the bracket to check. JEE Main 2014 (09 Apr Online) JEE Main Previous Year Paper (1) OR (A = 1, B = 1, Y = 0) (2) XOR (A = 0, B = 0, Y = 0) (3) NOT (A = 1, B = 1, Y = 1) (4) AND (A = 1, B = 1, Y = 1)

Q29.Long-range radio transmission is possible when the radio waves are reflected from the ionosphere. For this to happen the frequency of the radio waves must be in the range: (1) 150 −500 kHz (2) 80 −150 MHz (3) 1 −3 MHz (4) 8 −25 MHz

Q30.For sky wave propagation, the radio waves must have a frequency range in between: (1) 1MHz to 2MHz (2) 5MHz to 25MHz (3) 35MHz to 40MHz (4) 45MHz to 50MHz