What is true of energy stored in electric field?
  • Energy remains unchanged
  • Energy decrease by the factor i
  • Energy increase by the factor i
  • None of these
What happens the to the capacitance ?
  • Capacitance increases
  • Capacitance decreases
  • Capacitance remains unchanged
  • insufficient information
An object lying on a long horizontal conveyer belt moving at a constant velocity v receives a velocity v0= 5m/s relative to the ground in the direction opposite to the direction of the motion of conveyer. After t=4s, the velocity of the block becomes equal to the velocity of the belt. The coefficient of friction between the block and the belt is μ=.2 What is the value of ratio v/v0
  • 1/5
  • 3/5
  • 2/5
  • 4/5
Link Comprehension Type Use this answer Questions 2,3 and 4 A 10μF capacitor is connected  through a 1000ohm resistance to a constant Potential difference of 100 V  Find the current in the circuit at t=0
  • .1 A
  • 10 A
  • 2 A
  • 5 A
Find the time in which the capacitor will acquire its half charge
  • $.693 \times 10^{-2}$
  • $.2 \times 10^{-2}$
  • $.5 \times 10^{-3}$
  • $.25 \times 10^{-3}$
Find the current at t=10-2 sec
  • .0368 A
  • .368 A
  • .1 A
  • 1.25 A
An object is shot with an initial velocity 20 m/s at an angle of 600 with the horizontal. At the top of the trajectory ,the object explodes into two fragments of equal mass. One fragment whose speed immediately after the explosion is zero, falls vertically.  How far from the gun does the other fragment land.
  • 20 m
  • 53 m
  • 30m
  • None of the above
A cross-section of the long cylindrical conductor of radius R1 containing a long cylindrical hole of RThe axes of the cylinder and hole are parallel and are at distance d apart. A current 1 Ampere is uniformly distributed over the cylindrical conductor. The magnetic field at the center of the hole is
  • $ \frac {(\mu _0 id)}{(2\pi (R_1^2-R_2^2))}$
  • Zero
  • $ \frac {(\mu _0 id)}{(2\pi (R_1^2+R_2^2))}$
  • $ \frac {(\mu _0 id)}{(4\pi (R_1^2-R_2^2))}$
A cylindrical drum  of mass M and radius R lies on the road against the curb which has height R/2 as shown in below figure.it is lifted gently quasistatiscally on the sidewalk by a rope wound around its circumference. What is the minimum force needed if the rope is pulled horizontally
  • $\frac {(mg2 \sqrt 3)}{3}$
  • $\frac {(mg\sqrt 3)}{2}$
  • $\frac {(mg\sqrt 3)}{4}$
  • $\frac {(mg\sqrt 3)}{3}$
When a block of iron floats in mercury ay 00 C , a fraction  i1 of its volume is submerged while at the temperature 600 C ,a fraction i2  is seen to be submerged. If the coefficient  of volume expansion of iron is kfe and that of mercury is khg ,then  which of these statement is true
  • $i_1 (1-60K_{fe} )-i_2 (1+60K_{hg} )=0$
  • $i_1 (1+60K_{fe} )-i_2 (1+60K_{hg} )=0$
  • $i_1 (1+60K_{fe} )-i_2 (1-60K_{hg} )=0$
  • $i_2 (1+60K_{fe} )-i_1 (1+60K_{hg} )=0$
The refractive index of the material of an equilateral prism is  $\sqrt 3 $ . What is the angle of minimum deviation?
  • 60°
  • 25°
  • 30°
  • 15°
Two beams of light having intensities I and 9I interfere to produce a fringe pattern on a screen . The phase difference between the beams is π/2 at X and π at point Y. Let IX and IY be the resultant intensities at point X and  Y. Which of these is true?
  • $I_X –I_Y=4I$
  • $I_X –I_Y=6I$
  • $I_X –I_Y=2I$
  • None of these
A mass m=.2 Kg  and a spring of spring constant K=.5 N/m lie on a smooth horizontal table . The mass is released at x=.1 m from its equilibrium position. At what time t,the mass passes through point A which is at distance .02 m from equilibrium position first time.
  • .1 sec
  • .87 sec
  • .6 sec
  • .5 sec
The electron emitted in beta radiation originates from
  • Photon escaping from the nucleus
  • Inner orbits of atoms
  • Free electrons existing in nuclei
  • decay of a neutron in a nucleus

  • The equivalent resistance between A and B is 3R/2
  • The equivalent resistance between A and C is 5R/8
  • The equivalent resistance between B and C is 3R/8
  • None of these
The maximum number of possible interference  maxima for slit –separation equal to the twice of wavelength in Young’s double slit experiment is
  • Five
  • Four
  • Three
  • Zero
An electric dipole consisting of two opposite charges of 2X10-6 C each separated by a distance of 3 cm is placed in an electric field of 2 X105 N/C. The maximum torque on the dipole will be
  • $12 \times 10^{-3}$ Nm
  • $36 \times 10^{-3}$ Nm
  • $12 \times 10^{-1}$ Nm
  • $12 \times 10^{-2}$ Nm
Three identical charged particles each possessing the mass m and charge +q are placed at the corner of the equilateral triangle of side a. Then the particles are simultaneously set free and start flying apart symmetrically due to coulomb repulsion force. Find the velocity of each particle as they move large distance apart
  • $\sqrt {\frac {(8\pi \epsilon _0 q^2)}{ma}}$
  • $\sqrt {\frac {(4\pi \epsilon _0 q^2)}{ma}}$
  • $\sqrt {\frac {(8\pi \epsilon _0 q^2)}{a}}$
  • None of the these
The photoelectric work function of potassium is 2.0 eV . if Light having a wavelength of 360nm falls on potassium.  Let x be the stopping potential and y be the kinetic energy in electron volt of the most energetic electrons ejected?
  • x=1.45 eV , y=1.45 eV
  • x=1.25eV, y=1.45 eV
  • x=1.45 eV, y=1.25 eV
  • None of these
A satellite is moving around  the earth in a stable circular orbit. Which one of these is  not true
  • Its angular momentum is constant
  • It is moving with constant speed
  • it behaves as if it were as freely falling body
  • It is acted upon by a force directed away from center of the earth which counter balances the gravitational pull of the earth
Two equal spheres X and Y lie on a smooth horizontal circular groove at opposite ends of a diameter. Sphere X is projected along the groove and at the end of time I impinge on sphere Y. If e is the coefficient of restitution, the second impact will occur after a time equal to
  • T
  • eT
  • 2T/e
  • 2eT
An alternating current containing a resistance of 10 ohm and inductance of 1/10π henry in series is connected with a 100 V AC of 50 cycles/second . Power loss in the circuit is
  • 400 W
  • 500 W
  • 376 W
  • 424 W
An object of mass m is acted upon by the constant force and start from rest and it covers a distance d in some time. The kinetic energy( K) acquired by the body is
  • is directly proportional to $\sqrt m$
  • is directly proportional to m
  • is directly proportional to $1/\sqrt {m} $
  • independent of m
Link Comprehension Type Use this answer Questions 2,3 and 4 Two circuit X and Y connected to same E  Volt DC-source have self inductance L1 and L2 respectively ( L1 > L2) and equal resistance of R ohm each. Let Ix and Iy be the steady state current in Circuit X and Y respectively   Which is the appropriate relation for steady state current  in Circuit X and Circuit Y?
  • Ix  > Iy
  • Ix  < Iy
  • Ix = Iy
  • Cannot say on this
Let tx and ty be the time taken by the current in respective circuit to reach (1- 1/e)  of their steady state value. Which is the appropriate relation between tx and ty  ?
  • tx  > ty
  • tx  < ty
  • tx = ty
  • Cannot say on this
Let PX and PY  be the power dissipated  in the circuit to build up its current to the steady value. Which is the appropriate relation between tx and ty  ?
  • PY  > PX
  • PY  < PX
  • PX = PY
  • Cannot say on this
A solid cylinder of mass M and radius R rolls downs an inclined plane of height H. which of the following statement is false
  • The translational energy is 2/3 of the initial energy when the cylinder rolls down to the bottom of the incline
  • The Rotational energy at the bottom of the incline plan is ½ of the translational energy at the bottom
  • Angular velocity at the bottom is $ \frac {2}{R} \sqrt {\frac {gH}{3}}$
  • None of the above
An AC current is given by the expression $i= p cos \omega t + q sin \omega t$ The rms value of the current will be
  • p +q
  • $(p^2 + q^2)/2$
  • $\frac {\sqrt {p^2 -q^2}}{2}$
  • $\frac {\sqrt {p^2 +q^2}}{2}$
A box of mass M is pulled by a man holding a rope  at an angle θ to the horizontal .A second man pulls the box horizontally in the opposite direction with a force equal to twice the weight of the box.What is the maximum value of θ such that the box begins to move in the direction of first man without being lifted up?
  • 26.57°
  • 33.3°
  • 57°
  • None of these
The maximum velocity of photoelectrons emitted from a metal surface is 1.76 X106 m/s. If the e/m ratio of an electron is 1.76X1011 C/kg. ,then the stopping potential of the metal is
  • 8.8V
  • 6.6 V
  • 4.4 V
  • 2.2 V
0 h : 0 m : 1 s