(1) If A= 6i-8j, then 4A has the magnitude:
(a) 40 (b) 10 (c) 20 (d) None of these
2) Let A= 2i+6j-3k and B= 4i+2j+k then A.B equals:
(a) 8i+12j-3k (b) 17 (c) 23 (d) None of these
3) If V is an operator, then V.V means:
(a) Gradient of a Scalar field
(b) Curl of a vector field
(c) Divergence of a Vector field
(d) None of these
4) The volume of a parallelepiped bounded by Vectors A,B and C can be obtained from the:
(a) ( A x B ).C
(b) (A.B)x C
(c) ( A x B ) x C
(d) None of these
5) A force acting on a particle is conservative if:
(a) It obeys Newton’s third law
(b) It obeys Newton’s second law
(c) It works equals the change in Kinetic energy
(d) None of these
6) A torque applied to a rigid object always tends to produce:
(a) A rotational acceleration
(b) A linear acceleration
c) Precision
(d) None of these
7) When the velocity of a body is constant, its acceleration is:
(a) Maximum (b) Zero (c) Infinity (d) None of these
8) In the absence of external torque the total angular momentum is:
(a) Constant (b) Zero (c) infinity (d) None of these
9) The rate of change of Momentum of the particle is:
(a) Energy (b) Force (c) Impulse (d) None of these
10) The intensity of a wave is proportional to the square of:
(a) Amplitude (b) Time (c) Intensity (d) None of these
11) The colours in soap bubbles, oil slick etc. in a thin film is due to:
(a) Diffraction
(b) Polaristaion
(c) Interference
(d) None of these
12) For higher resolution, in a diffraction grating, one needs to have:
(a) Large number of ruling
(b) Small number of ruling
(c) No rulings at all
(d) None of these
13) To produce interference, the sources must be:
(a) Intense (b) Incoherent (c) Coherent (d) None of these
14) Interference fringes are of:
(a) Unequal width (b) Equal width (c) Variable width (d) None of these
15) A Carnot Cycle is:
(a) a rectangle on a P-V graph
(b) bounded by two isotherms and two adiabatics
(c) any four sided process on a P-V graph
(d) None of these
16) In an Adiabatic process:
(a) The temperature of the system remains constant
(b) The temperature of the system must change
(c) The internal energy of the system remains constant
(d) None of these
17) A Carnot Cycle heat engine operates between 227°C and 127° C. Its efficiency is:
(a) 44% (b) 20% (c) 79% (d) None of these
18) Metals pipe carrying water some times bursts in winter because:
(a) Water expands
(b) Ice expands when melts
(c) Metal contracts more than water
(d) None of these
19) A Fahrenheit thermometer and Celsius thermometer shows the same reading at:
(a) 200° (b) -40° (c) 100° (d) None of these
20) Constructive and destructive superposition of waves is observed in:
(a) Polarisation
(b) Interference
(c) Diffraction
(d) None of these
21) A Watt – sec is a unit of:
(a) Force (b) Energy (c) Power (d) None of these
22) The direction of any magnetic induction effect is such as to oppose the cause of the effect. This is:
(a) Coulumb’s Law
(b) Ampere’s Law
(c) Lenz’s Law
(d) None of these
23) A magnetic field cannot:
(a) accelerate a charge
(b) Exert a force on a charge
(c) change the kinetic energy of a charge
(d) None of these
24) The inverse of resistivity is called Conductivity. Its unit is:
(a) Ohm-1
(b) ohm-metre
(c) (ohm-meter)-1
(d) None of these
25 An LRC Circuit has R= 4O, Xc = 3 and XL=6, the impedence of the circuit is:
(a) 5 O (b) 7 O (c) 13 O (d) None of these
26) A “step-down” transformer is used to:
(a) increase the power
(b) decrease the voltage
(c) Increase the voltage
(d) None of these
27) Electrical potential is the potential energy per unit:
(a) Charge (b) Voltage (c) Force (d) None of these
28) The force on a charge moving with the velocity in a magnetic field B is given by:
(a) F = (q/v x B)
(b) F = ( qv x B )
(c) F = (qv + B)
(d) None of these
29) A changing current “i” in any circuit induces an emf “e” in that circuit, which is equal to:
(a) e = di/dt (b) E = i dF/dt (c) e = – L di/dt (d) None of these
30) Inductive reactance of an inductor is:
(a) XL= ?2L (b) XL= ?/L (c) e = -L di/dt (d) None of these
31) The resonant frequency of an LC-Circuit is:
(a) f = 2? LC (b) f = 1 / 2?√ LC (c) f = 1/ 2LC (d) None of these
32) The deliberate addition of an impurity element in a semi-conductor is called:
(a) doping (b) annealing (c) mixing (d) None of these
33) The conversion of AC into DC is called:
(a) amplification
(b) rectification
(c) modulation
(d) None of these
34) The Laser light is:
(a) monochromatic
(b) coloured
(c) chromatic
(d) None of these
35) The Laser light may be obtained from:
(a) quartz crystal
(b) NaCl crystal
(c) ruby crystal
(d) None of these
36) The emission of photoelectrons in photoelectric effect is dependent on:
(a) threshold frequency
(b) intensity of light
(c) Nature of metal
(d) None of these
37) Which one of the following is NOT needed in Nuclear Fission reactor:
(a) fuel (b) accelerator (c) moderator (d) None of these
38) The half life of a radioactive isotope is 140 days. How many days would it take to loose 3/4 of its initial activities:
(a) 105 days (b) 280 days (c) 35 days (d) None of these
39) Most of the energy produced in Sun is due to:
(a) Nuclear fusion
(b) Chemical reaction
(c) Nuclear Fission
(d) None of these
40) A U-235 nucleus will split when it captures:
(a) an a-particle (b) e.m. radiation (c) neutron (d) None of these
41) Two particles each of mass 5.0kg are mounted 4.0m apart on a mass-less light rod which is capable of rotation about its center? The moment of inertia is:
(a) 1.25 kgm2(b) 20 kgm2(c) 40 kgm2(d) None of these
42) The time period of mass of 1kg attached to a spring of spring constant of 100N/m is:
(a) 0.2p(b) p(c) 2p(d) None of these
43) A 14cm inner diameter water main furnishes water (through intermediate pipes) to a 1.00cm inner diameter faucet pipe. If the average speed in the faucet pipe is 3.0 cm/s, what will be the average speed it causes in the water main?
(a) 0.015 cm/s (b) 0.15 m/s (c) 0.5 m/s (d) None of these
44) What is the tension T in the rope if a 10N weight is being pulled upward by it with a constant velocity of 2m/s?
(a) 12N (b) 8N (c) 5N (d) None of these
45) The ratio of linear Stress/Linear Strain is called:
(a) Young’s Modulus
(b) Bulk Modulus
(c) Deformation
(d) None of these
46) A body is moving with constant speed in a circle, its velocity vector:
(a) Remains constant
(b) Changes its magnitude
(c) Changes its direction
47) When a constant torque is acting on a rotating system, which of the following is constant?
(a) Angular velocity
(b) Angular acceleration
(c) Angular momentum
48) A geo-stationary satellite revolves around the earth from:
(a) East to west
(b) West to east
(c) North to south
(d) None of these
49) According to Einstein, with the great increase in the speed of a body, the relativistic is:
(a) Length remains constant
(b) Time decreases
(c) Mass increases
(d) None of these
50) A body is moving northward and the force applied is eastward, the acceleration produced is:
(a) Northward
(b) At 45oEast of North
(c) Eastward
(d) None of these