Vr's JEE Mock Test -1

90 Questions | Total Attempts: 59

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INSTRUCTIONS The Mock Test consists of 90 questions. The maximum marks are 360. The test is of 3 hours duration. There are three parts in the question paper A, B, C consisting of, Physics, Chemistry and Mathematics having 30 questions in each part of equal weightage. Each question is allotted 4 (four) marks for each correct response. 1/4 (one fourth) marks will be deducted for indicating incorrect response of each question. No deduction from the total score will be made if no response is indicated for an item in the answer sheet. There is only one correct response for each question. Filling up more than one response in each question will be treated as wrong response and marks for wrong response will be deducted accordingly.


Questions and Answers
  • 1. 
    A capacitance of 2 μF is required in an electrical circuit across a potential difference of 1.0 kV. A large number of 1 μF capacitors are available which can withstand a potential difference of not more than 300 V. The minimum number of capacitors required to achieve this is :
    • A. 

      2

    • B. 

      16

    • C. 

      24

    • D. 

      32

  • 2. 
    A student measured the length of a rod and wrote it as 3.50 cm. Which instrument did he use to measure it ?
    • A. 

      A screw gauge having 100 divisions in the circular scale and pitch as 1 mm.

    • B. 

      A screw gauge having 50 divisions in the circular scale and pitch as 1 mm.

    • C. 

      A meter scale

    • D. 

      A vernier calliper where the 10 divisions in vernier scale matches with 9 division in main scale and main scale has 10 divisions in 1 cm.

  • 3. 
    A mass ‘m’ is supported by a massless string wound around a uniform hollow cylinder of mass m and radius R. If the string does not slip on the cylinder, with what acceleration will the mass fall on release?
    • A. 

      5g/6

    • B. 

      2g/3

    • C. 

      G/2

    • D. 

      G

  • 4. 
    Three conducting rods of same material and cross-section are shown in figure. Temperatures of A, D and C are maintained at 20°C, 90°C and 0°C. The ratio of lengths of BD and BC if there is no heat flow in AB is -
    • A. 

      2/7

    • B. 

      7/2

    • C. 

      9/2

    • D. 

      2/9

  • 5. 
    The density of water at 20°C is 998 kg/m3 and at 40°C 992 kg/m3. The coefficient of volume expansion of water is
    • A. 

      10–4/°C

    • B. 

      3 × 10–4/°C

    • C. 

      2 × 10–4/°C

    • D. 

      6× 10–4/°C

  • 6. 
    The fundamental frequency of a closed organ pipe of length 20 cm is equal to the second overtone of an organ pipe open at both the ends. The length of organ pipe open at both ends is
    • A. 

      80 cm

    • B. 

      100 cm

    • C. 

      120 cm

    • D. 

      140 cm

  • 7. 
    When a mass is rotating in a plane about a fixed point, its angular momentum is directed along:
    • A. 

      The line perpendicular to the plane of rotation

    • B. 

      The line making an angle of 45° to the plane of rotation

    • C. 

      The radius

    • D. 

      The tangent to the orbit

  • 8. 
    One way in which the operation of a n-p-n transistor differs from that of a p-n-p
    • A. 

      The emitter junction is reversed biased in n-p-n

    • B. 

      The emitter junction injects minority carriers into the base region of the p-n-p

    • C. 

      The emitter injects holes into the base of the p-n-p and electrons into the base region of n-p-n

    • D. 

      The emitter injects holes into the base of n-p-n

  • 9. 
    A current of 2.5 A flows through a coil of inductance 5 H. The magnetic flux linked with the coil is
    • A. 

      2 Wb

    • B. 

      0.5 Wb

    • C. 

      ZERO

    • D. 

      12.5 Wb

  • 10. 
    The magnetic field in a travelling electromagnetic wave has a peak value of 20 nT. The peak value of electric field strength is
    • A. 

      6 V/m

    • B. 

      9 V/m

    • C. 

      3 V/m

    • D. 

      12 V/m

  • 11. 
    In a series LCR circuit R = 200 Ω and the voltage and the frequency of the main supply is 220 V and 50 Hz respectively. On taking out the capacitance from the circuit the current lags behind the voltage by 30°. On taking out the inductor from the circuit the current leads the voltage by 30o. The power dissipated in the LCR circuit is
    • A. 

      305 W

    • B. 

      242 W

    • C. 

      ZERO

    • D. 

      210 W

  • 12. 
    What is the minimum energy required to launch a satellite of mass m from the surface of a planet of mass M and radius R in a circular orbit at an altitude of 2R? 
    • A. 

      2GmM /3R

    • B. 

      GmM /3R

    • C. 

      5GmM /6R

    • D. 

      GmM /2R

  • 13. 
    Transverse elastic waves can propagate –
    • A. 

      Both in a gas and a metal

    • B. 

      In a gas but not in a metal

    • C. 

      In a metal but not in a gas

    • D. 

      Neither in a gas nor in a metal

  • 14. 
    Two long parallel wires separated by a distance r have equal currents I flowing in each. Either wire experiences a magnetic force F N/m. If the distance r is increased to 3r and current in each wire is reduced to I/3, the force between them will now be -
    • A. 

      3F N/m

    • B. 

      9F N/m

    • C. 

      (F/9) N/m

    • D. 

      (F/27) N/m

  • 15. 
    Two cars moving in opposite directions approach each other with speed of 22 m/s and 16.5 m/s respectively. The driver of the first car blows a horn having a frequency 400 Hz. The frequency heard by the driver of the second car is [velocity of sound 340 m/s]
    • A. 

      350 Hz

    • B. 

      361 Hz

    • C. 

      411 Hz

    • D. 

      448 Hz

  • 16. 
    A potentiometer is an accurate and versatile device to make electrical measurements of E.M.F, because the method involves :
    • A. 

      Cells

    • B. 

      Potential gradients

    • C. 

      A condition of no current flow through the galvanometer

    • D. 

      A combination of cells, galvanometer and resistances

  • 17. 
    A person trying to lose weight by burning fat lifts a mass of 10 kg upto a height of 1 m 1000 times. Assume that the potential energy lost each time he lowers the mass is dissipated. How much fat will he use up considering the work done only when the weight is lifted up? Fat supplies 3.8 × 107 J of energy per kg which is converted to mechanical energy with a 20% efficiency rate. Take g = 9.8 ms–2 :-
    • A. 

      12.89 × 10–3 kg

    • B. 

      9.89 × 10–3 kg

    • C. 

      2.45 × 10–3 kg

    • D. 

      6.45 × 10–3 kg

  • 18. 
    An observer looks at a distant tree of height 10 m with a telescope of magnifying power of 20. To the observer the tree appears :
    • A. 

      20 times nearer

    • B. 

      10 times taller

    • C. 

      10 times nearer

    • D. 

      20 times taller

  • 19. 
    Hysteresis loops for two magnetic materials A and B are given below : These materials are used to make magnets for electric generators, transformer core and electromagnet core. Then it is proper to use ;
    • A. 

      B for electromagnets and transformers.

    • B. 

      A for electric generators and transformers.

    • C. 

      A for electromagnets and B for electric transformers.

    • D. 

      A for transformers and B for electric generators

  • 20. 
    The pressure that has to be applied to the ends of a steel wire of length 10 cm to keep its length constant when its temperature is raised by 100°C is : (For steel Young’s modulus is 2 × 1011 N m−2 and coefficient of thermal expansion is 1.1 × 10−5 K−1)
    • A. 

      2.2×10^7 Pa

    • B. 

      2.2×10^6 Pa

    • C. 

      2.2×10^8 Pa

    • D. 

      2.2×10^9 Pa

  • 21. 
    A beam of unpolarised light of intensity I0 is passed through a polaroid A and then through another polaroid B which is oriented so that its principal plane makes an angle of 45° relative to that of A. The intensity of the emergent light is :
    • A. 

      Io

    • B. 

      Io/2

    • C. 

      Io/4

    • D. 

      Io/8

  • 22. 
    When the current i flowing through a conductor, the drift velocity is v. If 2i current is flowed through the same metal but having double the area of cross section, the drift velocity will be
    • A. 

      V/4

    • B. 

      V

    • C. 

      V/2

    • D. 

      2V

  • 23. 
    A particle is executing linear simple harmonic motion amplitude A. What fraction of the total energy is kinetic when the displacement is half the amplitude.
    • A. 

      1/2

    • B. 

      1/4

    • C. 

      3/4

    • D. 

      2

  • 24. 
     A student measures the time period of 100 oscillations of a simple pendulum four times. The datasetis90s,91s,95sand92s.Iftheminimum division in the measuring clock is 1 s, then the reported mean time should be :-
    • A. 

      92 ± 3 s

    • B. 

      92 ± 2 s

    • C. 

      92 ± 5 s

    • D. 

      92 ± 1.8 s

  • 25. 
    Two cars of masses m1 and m2 are moving in circles of radii r1 and r2, respectively. Their speeds are such that they make complete circles in the same time t. The ratio of their centripetal acceleration is
    • A. 

      M1r1 :m2r2

    • B. 

      M1 :m2

    • C. 

      1:1

    • D. 

      R1: r2

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