Wednesday 24 April 2013

Physics test chapter 15+16 (2) (Answer key)


1.c

2.a

3.b

4.c

5.a

6.c

7.b

8.a

9.B( dono se same current pas ho ga. 25 W waly bulb ko thora current chahye aur 100 W waly bulb ko zyada current chahye. For this reason 25 W bulb will grow bighter)

10.b

Physics test chapter 15+16 (2)


1.     Which of the following is produced first
a)     Induced emf
b)    Induced current
c)     Motional emf
d)    None of above


2.     If a closed metallic loop is moved across a magnetic field then
a)     Induced current is produced in it
b)    No induced current is produced
c)     Magnetic will attract the loop
d)    None of these


3.     The phenomenon by which an induced emf is produced in the conductor due to magnetic flux in it is called
a)     Electromagnetism
b)    Electromagnetic induction
c)     Electric polarization
d)    All of the above


4.     The circuit in which current and voltage are in phase, the power factor is
a)     Doubled
b)    Negative
c)     One
d)    Zero


5.     The phase angle between the voltage and the current in an AC circuit consisting of a resistance is
a)     Zero
b)    450
c)     900
d)    1800


6.     Pure coke consumes
a)     Minimum power
b)    Maximum power
c)     No power
d)    Average power


7.     Who derived the velocity of Electromagnetic waves
a)     Faraday
b)    Maxwell
c)     Lenz
d)    Einstein


8.     Electromagnetic waves travel in free space with the speed of
a)     gamma-rays
b)    Positive rays
c)     Cathode rays
d)    Β-rays


9.     25 watt and 100 watt bulbs are joined in series and connected to the mains. Which bulb will glow brighter?
a)     100W
b)    25W
c)     First 25W and then 100W
d)    None of these


10.                        For ideal transformer, Vs is _______ proportional to Is.
a)     Directly
b)    Inversely
c)     Both a and b
d)    None of these


Monday 22 April 2013

Chemistry test Chapter 4 Book 1 (Answer key)



1.c

2.a

3.a

4.a

5.c

6.c

7.b

8.a

9.a

10.d

11.a

12.C

13.d

14.b

15.d

16.c

17.b

Chemistry Test Chapter 4 book 1


1.     Sugar is an example of
a)     Ionic crystal
b)    Covalent crystal
c)     Molecular crystal
d)    Metallic crystal


2.     Electron sea theory was proposed by
a)     Drude
b)    Loren
c)     Pauling
d)    Fritz London



3.     Give the name of following system a≠b≠c ; alpha=gama=900 ;  beta ≠900
a)     Monoclinic
b)    Orthorhombic
c)     Tetragonal
d)    Triclinic


4.     Which functional group is present in glucose
a)     CHO
b)    C2O4
c)     C2O2
d)    COOH


5.     Maximum packing efficiency which is present in crystals is
a)     62%
b)    72%
c)     74%
d)    100%


6.     74% packing efficiency is associated with ______ crystalline system
a)     Hexagonal
b)    Face centered cubic
c)     Both a and b
d)    Monoclinic


7.     By increasing size of ion, lattice energy
a)     Increases
b)    Decreases
c)     Remains constant
d)    Is not regularly changed


8.     Which of the following is face centered cubic arrangement
a)     ABC-ABC
b)    AB-AB
c)     ACB-ACB
d)    CBA-ABC


9.     Nature of copper crystal is
a)     Metallic
b)    Ionic
c)     Covalent
d)    Molecular


10.                        Ionic solids are characterized by the
a)     Low melting point
b)    Good conductivity in solid state
c)     High vapor pressure
d)    Solubility in the polar solvent


11.                        Mostly crystals show good cleavage because their atoms, ions or molecules are
a)     Arranged in planes
b)    Weakly bonded together
c)     Spherically symmetric
d)    Strongly bonded together


12.                        The coordination number of a body centered atom in a crystal is
a)     4
b)    6
c)     8
d)    12


13.                        Metallic bond has been explained by a number of theories, LIUS PAULING has proposed the theory
a)     MOT
b)    Electron Gas theory
c)     Band theory
d)    VBT


14.                        Hardness of diamond is attributed to the
a)     Strength of ionic bond in the structure
b)    Three dimensional net work of covalent bond
c)     Absence of valence electron in C atom
d)    Tetrahedral geometry of each carbon atom


15.                        All the metals shine when they are freshly cut because
a)     Conductivity of metal increases
b)    Cutting process gives energy to metal atoms
c)     Electron become less delocalized
d)    Excited electron emits energy when de-excited



16.                        Existences of different compound in the same crystalline form is called
a)     Anisotropy
b)    Polymorphism
c)     Isomorphism
d)    Allotropy


17.                        Ionic solids become brittle under stress because
a)     Ionic solids are unable to bear stress
b)    Same ions start repelling each other
c)     This is the property of ionic solids
d)    All ionic solids do not show same behavior


Sunday 21 April 2013

Chemistry MCQs Chapter 4 book 1


1.     Vapor pressure of diethyl ether at 00C is approximately
a)     4.8 torr
b)    100 torr
c)     200 torr
d)    250 torr



2.     Lattice energy for the formation of NaCl crystal is
a)     -787KJmol-1
b)    +787KJmo-1
c)     -787 KCalmol-1
d)    +787 Calmol-1



3.     Crystallographic elements are determined for any crystalline substance which decides its structure, the best technique used for this purpose is
a)     Mass spectrometer
b)    Barometer
c)     X-ray diffraction
d)    None of these







1.c
2.a
3.c

Chemistry MCQs Chapter 4 book 1


1.     Sulphate and chromate both are tetrahedral so they are ________ of each other
a)     Isomorph
b)    Polymorph
c)     Anisotropic
d)    Enantiomers


                                       

2.     If any substance ‘X’ has melting point of 4000C and it is crystalline, then transition temperature of this may be
a)     Greater than 4000C
b)    Should be less than  4000C
c)     Equal  to 4000C
d)    Cannot be decided without experimental verification




3.     Vapor pressure does not depend upon
a)     Temperature
b)    Surface area
c)     Intermolecular forces
d)    All of these








1.a
2.b
3.b


Chemistry MCQs Chapter 4 book 1


1.     Rising of liquid in a capillary tube is due to
a)     Surface tension
b)    Cohesive forces
c)     Adhesive forces
d)    Viscosity





2.     Boiling point of water at Mount Everest is
a)     980C
b)    690C
c)     1000C
d)    700C





3.     10% urea in NaCl changes the shape of crystal because
a)     It reacts chemically with NaCl
b)    It disturbs packing of ions in crystal
c)     Urea itself is not crystalline
d)    Urea do not interact with NaCl










1.C(between glass and liquid)
2.b
3.b