Q.1
• Mg
• .7mg
• mg
• 1.3mg
Q.2
##### When a ray of light enters a glass slab from air
• Wavelength decreases
• Frequency increase
• Neither wavelength nor frequency changes
• None of these
Q.3
##### A pool ball of mass m and radius r is given initial sliding velocity v0 ( no rotation) on a horizontal pool table.how long will it take for ball to start pure rolling if the coefficient of friction between ball and table is k?
• $\frac {2v_0}{7kg}$
• $\frac {7v_0}{2kg}$
• $\frac {v_0}{kg}$
• None of the above
Q.4
##### Two person X and Y,each carrying a source of sound of frequency k are standing a few meters apart in a quiet field. X starts moving towards Y with the velocity a .If b is the speed of sound,how many beats will be heard per sec by A?
• $ka(b-a)$
• $\frac {2ka}{a+b}$
• $\frac {2ka}{b}$
• $\frac {ka}{b}$
Q.5
##### A monochromatic point source of light is at a distance of .2 m from a photo electric cell,the saturation current and cutoff voltage are 18 mA and .6 Volt respectively.If the same source is placed at .6 m away from the photo electric cell,then
• stopping voltage=.6 V,Saturation current =2 mA
• stopping voltage=.6 V,Saturation current = mA
• stopping voltage=.6 V,Saturation current =3 mA
• stopping voltage=.16 V,Saturation current =2 mA
Q.6
##### A proton is released from rest in a region of steady and uniform Electric Field E and Magnetic Field B which are parallel to each other. The proton trajectory will be
• Circle
• Straight line
• helix
• cycloid
Q.7
##### Three capacitors have capacitance's of C F, 2C F and 3C F respectively. They are first connected to have maximum capacitance and then connected to have minimum capacitance. Find the ratio of maximum capacitance to minimum capacitance.
• 6
• 5
• 11
• None of these
Q.8
##### A flat bad truck carries a box. The coefficient of friction between the box and truck is .3 What is the maximum acceleration the driver can have so that box does not slide? Take g=10 m/s2
• Data not sufficient
• .3 m/s2
• 3 m/s2
• None of these
Q.9
##### Two electron are released towards each other with equal velocities of 106 m/s. What is the closest distance between them?
• $3.56 \times 10^{-10}$ m
• $2.56 \times 10^{-7}$ m
• $1.6 \times 10^{-10}$ m
• $2.56 \times 10^{-10}$ m
Q.10
##### A heater boils a certain quantity of liquid in time x. Another heater boils the same quantity of liquid in time y. If the both the heater are connected in parallel,the combination will boil the liquid in time
• $\frac {1}{x}+ \frac {1}{y}$
• $x +y$
• $\frac {x+y}{2}$
• $\sqrt {xy}$
Q.11
##### The effective capacitance of a number of capacitor connected in series is p F ,When one of the capacitor is removed,the The effective capacitance is q F.The capacitance of the capacitor which is removed
• $q-p$
• $\frac {pq}{p+q}$
• $\frac {pq}{q-p}$
• None of these
Q.12
• 110 J
• 70 J
• 10 J
• 170 J
Q.13
##### A U tube containing a liquid is accelerate horizontally with constant acceleration a .The separation between the limb's is L. The Difference in the height of the liquid in the two arms would be
• $L\sqrt { \frac {a}{g}}$
• $\frac {aL}{g}$
• $\frac {L}{2}$
• $\frac {a^2L}{g^2}$
Q.14
##### An elastic spring of un-stretched length L and force constant k is stretched by a small length a .It is further stretched by another small length b.The work done in first stretching and second stretching is W1 and WWhich of the following is true
• $W_1=\frac {Ka^2}{2} ,W_2=\frac {Kb^2}{2}$
• $W_1=\frac {Ka^2}{2} ,W_2=\frac {Kb(2a+b)}{2}$
• $W_1=\frac {Ka^2}{2} ,W_2=\frac {K(a^2+b^2)}{2}$
• $W_1=\frac {Ka^2}{2}, W_2= \frac {K(a+b)^2}{2}$
Q.15
##### Which of these is false for electric charge?
• e ($1.6 \times 10^{-19}$ C) is the elementary charge
• charge can not be destroyed or created
• 1 Coulomb of charge contain $6.25 \times 10^{17}$ electron
• Coulomb law of electric force between the charges follows Newton's third law of motion
• The net force on any charge equals the vector sum of the forces exerted on it by all the charges
Q.16
##### Electromotive force represents
• Work
• Momentum
• Power
• Energy per unit change
• Force
Q.17
##### Which of the following is False?
• Kirchhoff's first law of electric circuit is law of conservation charge
• Kirchhoff's second law of electric circuit is law of conservation of energy
• Kirchhoff's second law is based on law of conservation of momentum
• None of these
Q.18
##### Both electric forces and magnetic forces can deflect electron. Which of the following statement is false?
• Kinetic energy of the electron does not change in magnetic field
• Kinetic energy of the electron do change in electric field
• Kinetic energy neither changes in electric field nor in magnetic field
• None of these
Q.19
##### A particle is moving vertically downward.it passes through a magnetic field directed from south to north in a horizontal plane.which of the following is false?
• If the particle is positively charged ,it will be deflected towards east
• If the particle is negatively charged ,it will be deflected towards east
• If the particle has no charge ,it will not be deflected
• None of these
Q.20
##### A charged particle at rest experiences no forces. At the location of the particle
• electric field may or may not be zero, Magnetic Field must be zero
• electric field may or may not be zero, Magnetic Field may or may not be zero
• electric field must be zero,Magnetic Field must be zero
• electric field must be zero, Magnetic Field may or may not be zero
Q.21
• E > 0, B >0
• E=0,B=0
• E > 0,B=0
• E=0,B > 0
Q.22
##### A bar magnet falls vertical down through a coil placed in horizontal plane? What will be the acceleration of bar magnet?
• g
• greater than g
• less than g
• zero
Q.23
##### which of these are true?
• A conducting rod XY moves parallel to the x-axis in a uniform magnetic field pointing in +z direction.The end X is towards -y direction.The end X will be positively charged
• A square coil of metal wire is stationary in a non-uniform magnetic field,An Emf is induced in the coil
• The self inductance of the straight conductor is very large
• Lenz's law is a consequence of the law of conservation of charge
Q.24
##### An inductor stores energy in its
• Magnetic field
• Electric field
• electric and magnetic field both
• None of these
Q.25
##### which of these is not true for radioactive decay?
• The penetrating power of Gamma rays is highest among the radioactive radiation
• alpha and beta particles are deflected by electric and magnetic field but gamma rays are not
• None of these
Q.26
##### When a ray of light enters a glass slab from air?
• Wavelength decreases
• Frequency increase
• Neither wavelength nor frequency changes
• None of these
Q.27
##### Which of the these is true in Bohr model of hydrogen atom?
• The total energy of electron in the mth orbit is inversely proportional to m
• radiation are emitted when electron jumps from lower orbit to higher orbit
• The radius of the mth orbit is inversely proportional to m
• Angular momentum of the electron in mth orbit is an integral multiple of $\frac {h}{2 \pi}$
Q.28
##### In an AC circuit, which of these is true?
• The applied instantaneous voltage equal to the algebraic sum of the instantaneous voltages across the different element
• The applied instantaneous voltage equal to the vector sum of the instantaneous voltages across the different element
• Power dissipation happens in inductor and resistance in an AC circuit
• None of these
Q.29
• decrease
• increase
• cannot say
Q.30
##### What is true about electric field between the plates
• electric field remains unchanged
• electric field decrease by the factor i
• electric field increase by the factor i
• None of these