# Lecturer Physics Online Past MCQS Practice Test

Lecturer Physics Online Past MCQS Practice Test

Lecturer Physics Sample Papers, MCQs from Past Papers, Prepare Online Practice Test

(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
expression:
(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
(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= 4Ω, Xc = 3 and XL=6, the impedence of the circuit is:
(a) 5 Ω  (b) 7 Ω  (c) 13 Ω    (d) None of these   Next Page