12583 + Mcqs in Physics Page 24 McqOptions

1151.	The outer sphere of a spherical air capacitor is earthed. For increasing its capacitance [MP PET 1991]
A.	Vacuum is created between two spheres
B.	Dielectric material is filled between the two spheres
C.	The space between two spheres is increased
D.	The earthing of the outer sphere is removed
Answer» C. The space between two spheres is increased

Discussion

1152.	Weight of a body is maximum at [AFMC 2001]
A.	Moon
B.	Poles of earth
C.	Equator of earth
D.	Centre of earth
Answer» C. Equator of earth

Discussion

1153.	The unit of surface tension in SI system is [MP PMT 1984; AFMC 1986; CPMT 1985, 87; CBSE PMT 1993; KCET 1999; DCE 2000, 01]
A.	\[Dyne/c{{m}^{2}}\]
B.	\[I=\frac{Q}{t}=\frac{[Q]}{[T]}=[{{M}^{0}}{{L}^{0}}{{T}^{-1}}Q]\]
C.	\[Dyne/cm\]
D.	\[Newton/{{m}^{2}}\]
Answer» C. \[Dyne/cm\]

Discussion

1154.	A radioactive nucleus A with a half-life T, decays into a nucleus B. At \[t=0,\]there is no nucleus B. At some time t, the ratio of the number of B to that of A is 0.3. Then, t is given by
A.	\[t=T\log (1.3)\]
B.	\[t=\frac{T}{\log (1.3)}\]
C.	\[t=T\frac{\log 2}{\log 1.3}\]
D.	\[t=\frac{\log 1.3}{\log 2}T\]
Answer» E.

Discussion

1155.	Velocity at mean position of a particle executing S.H.M. is v, they velocity of the particle at a distance equal to half of the amplitude [RPMT 2001]
A.	4v
B.	2v
C.	\[\frac{\sqrt{3}}{2}v\]
D.	\[\frac{\sqrt{3}}{4}v\]
Answer» D. \[\frac{\sqrt{3}}{4}v\]

Discussion

1156.	If the binding energy per nucleon in \[L{{i}^{7}}\]and \[H{{e}^{4}}\] nuclei are respectively 5.60 MeV and 7.06 MeV, then energy of reaction \[L{{i}^{7}}+p\to 2{{\ }_{2}}H{{e}^{4}}\] is
A.	19.6 MeV
B.	2.4 MeV
C.	8.4 MeV
D.	17.3 MeV
Answer» E.

Discussion

1157.	A wheel having moment of inertia \[2\,kg-{{m}^{2}}\] about its vertical axis, rotates at the rate of 60 rpm about this axis. The torque which can stop the wheel's rotation in one minute would be
A.	1.12Nm
B.	0.83Nm
C.	0.55Nm
D.	0.21 Nm
Answer» E.

Discussion

1158.	A rod PQ of length is pivoted tan end P and freely rotated in a horizontal plane at an angular speed \[\omega \] about a vertical axis passing through P. If coefficient of line are x pansion of material of rod is \[\alpha \], find the percentage change in it sangular velocity if temperature of system is increased by \[\Delta \,T\] is
A.	\[(\alpha \,\Delta T\times 100)%\]%
B.	\[(2\alpha \,\Delta T\times 100)%\]%
C.	\[(3\alpha \,\Delta T\times 100)\times 100%\]%
D.	\[(4\alpha \,\Delta T\times 100)%\]%
Answer» C. \[(3\alpha \,\Delta T\times 100)\times 100%\]%

Discussion

1159.	A projectile thrown with a speed \[v\] at an angle \[\theta \] has a range \[R\] on the surface of earth. For same \[v\] and \[\theta \], its range on the surface of moon will be
A.	\[R/6\]
B.	\[6R\]
C.	\[R/36\]
D.	\[36R\]
Answer» C. \[R/36\]

Discussion

1160.	Sound waves of wavelength greater than that of audible sound are called [KCET 1999]
A.	Seismic waves
B.	Sonic waves
C.	Ultrasonic waves
D.	Infrasonic waves
Answer» E.

Discussion

1161.	Which of the following do not require medium for transmission [RPMT 2000]
A.	Cathode ray
B.	Electromagnetic wave
C.	Sound wave
D.	None of the above
Answer» C. Sound wave

Discussion

1162.	The work done in blowing a soap bubble of radius r of the solution of surface tension T will be [DPMT 1999; MP PMT 2003]
A.	\[8\pi {{r}^{2}}T\]
B.	\[2\pi {{r}^{2}}T\]
C.	\[4\pi {{r}^{2}}T\]
D.	\[\frac{4}{3}\pi {{r}^{2}}T\]
Answer» B. \[2\pi {{r}^{2}}T\]

Discussion

1163.	Electron volt is a unit of [MP PMT 2001]
A.	Potential
B.	Charge
C.	Power
D.	Energy
Answer» E.

Discussion

1164.	A sphere of mass m, moving with velocity V, enters a hanging bag of sand and stops. If the mass of the bag is M and it is raised by height h, then the velocity of the sphere was [MP PET 1997]
A.	\[\frac{M+m}{m}\sqrt{2gh}\]
B.	\[\frac{M}{m}\sqrt{2gh}\]
C.	\[\frac{m}{M+m}\sqrt{2gh}\]
D.	\[\frac{m}{M}\sqrt{2gh}\]
Answer» B. \[\frac{M}{m}\sqrt{2gh}\]

Discussion

1165.	Point masses 1, 2, 3 and 4 kg are lying at the points (0,0,0), (2,0,0), (0,3,0) and (-2, -2,0) respectively. The moment of inertia of this system about X-axis will be
A.	\[43\,kg\,{{m}^{2}}\]
B.	\[34\,kg\,{{m}^{2}}\]
C.	\[27\,kg\,{{m}^{2}}\]
D.	\[72\,kg\,{{m}^{2}}\]
Answer» B. \[34\,kg\,{{m}^{2}}\]

Discussion

1166.	A bird is sitting in a large closed cage which is placed on a spring balance. It records a weight of 25 N. The bird (mass m = 0.5 kg) flies upward in the cage with an acceleration of \[2\,m/{{s}^{2}}\]. The spring balance will now record a weight of [MP PMT 1999]
A.	24 N
B.	25 N
C.	26 N
D.	27 N
Answer» C. 26 N

Discussion

1167.	If the length of a wire is reduced to half, then it can hold the ......... load
A.	Half
B.	Same
C.	Double
D.	One fourth
Answer» C. Double

Discussion

1168.	When the number of turns in a coil is doubled without any change in the length of the coil, its self inductance becomes [MP PMT 1986; CBSE PMT 1992; Pb PET 2000]
A.	Four times
B.	Doubled
C.	Halved
D.	Unchanged
Answer» B. Doubled

Discussion

1169.	Water is used to cool radiators of engines, because
A.	Of its lower density
B.	It is easily available
C.	It is cheap
D.	It has high specific heat
Answer» E.

Discussion

1170.	Two spheres made of same substance have diameters in the ratio 1 : 2. Their thermal capacities are in the ratio of
A.	0.0430555555555556
B.	0.0472222222222222
C.	0.0444444444444444
D.	0.0840277777777778
Answer» C. 0.0444444444444444

Discussion

1171.	At atmospheric pressure, the water boils at \[100{}^\circ C\]. If pressure is reduced, it will boil at
A.	Higher temperature
B.	Lower temperature
C.	At the same temperature
D.	At critical temperature
Answer» C. At the same temperature

Discussion

1172.	The SI unit of mechanical equivalent of heat is
A.	Joule \[\times \] Calorie
B.	Joule/Calorie
C.	Calorie \[\times \] Erg
D.	Erg/Calorie
Answer» C. Calorie \[\times \] Erg

Discussion

1173.	A body of mass \[m\] moves in a circular path with uniform angular velocity. The motion of the body has constant [MP PET 2003]
A.	Acceleration
B.	Velocity
C.	Momentum
D.	Kinetic energy
Answer» E.

Discussion

1174.	A body of mass 10 kg is dropped to the ground from a height of 10 metres. The work done by the gravitational force is \[(g=9.8\,m/{{\sec }^{2}})\] [SCRA 1994]
A.	? 490 Joules
B.	+ 490 Joules
C.	? 980 Joules
D.	+ 980 Joules
Answer» E.

Discussion

1175.	Work done in splitting a drop of water of 1 mm radius into 106 droplets is (Surface tension of water \[=72\times {{10}^{-3}}J/{{m}^{2}})\] [MP PET/PMT 1988; CPMT 1989; RPET 2001]
A.	\[9.58\times {{10}^{-5}}\,J\]
B.	\[8.95\times {{10}^{-5}}\,J\]
C.	\[5.89\times {{10}^{-5}}\,J\]
D.	\[5.98\times {{10}^{-6}}J\]
Answer» C. \[5.89\times {{10}^{-5}}\,J\]

Discussion

1176.	Assertion : Under given conditions of pressure and temperature, sound travels faster in a monoatomic gas than in diatomic gas. Reason : Opposition for wave to travel is more in diatomic gas than monoatomic gas.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» D. If the assertion and reason both are false.

Discussion

1177.	Assertion : The speed of sound in solids is maximum though their density is large. Reason : The coefficient of elasticity of solid is large.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion.

Discussion

1178.	Assertion : On a rainy day sound travel slower than on a dry day. Reason : When moisture is present in air the density of air increases.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» E. If assertion is false but reason is true.

Discussion

1179.	An electron makes a transition from orbit n = 4 to the orbit n = 2 of a hydrogen atom. The wave number of the emitted radiations (R = Rydberg's constant) will be
A.	\[\frac{16}{3R}\]
B.	\[\frac{2R}{16}\]
C.	\[\frac{3R}{16}\]
D.	\[\frac{4R}{16}\]
Answer» D. \[\frac{4R}{16}\]

Discussion

1180.	According to Bohr's model, the radius of the second orbit of helium atom is
A.	0.53 \[\overset{\text{o}}{\mathop{\text{A}}}\,\]
B.	1.06 \[\overset{\text{o}}{\mathop{\text{A}}}\,\]
C.	2.12 \[\overset{\text{o}}{\mathop{\text{A}}}\,\]
D.	0.265 \[\overset{\text{o}}{\mathop{\text{A}}}\,\]
Answer» C. 2.12 \[\overset{\text{o}}{\mathop{\text{A}}}\,\]

Discussion

1181.	The ionisation potential of hydrogen atom is 13.6 volt. The energy required to remove an electron in the n = 2 state of the hydrogen atom is
A.	27.2 eV
B.	13.6eV
C.	6.8eV
D.	3.4eV
Answer» E.

Discussion

1182.	If a watch with a wound spring is taken on to the moon, it [AFMC 1993]
A.	Runs faster
B.	Runs slower
C.	Does not work
D.	Shows no change
Answer» E.

Discussion

1183.	What will be the force constant of the spring system shown in the figure [RPET 1996; Kerala (Med./ Engg.) 2005]
A.	\[\frac{{{K}_{1}}}{2}+{{K}_{2}}\]
B.	\[{{\left[ \frac{1}{2{{K}_{1}}}+\frac{1}{{{K}_{2}}} \right]}^{-1}}\]
C.	\[\frac{1}{2{{K}_{1}}}+\frac{1}{{{K}_{2}}}\]
D.	\[{{\left[ \frac{2}{{{K}_{1}}}+\frac{1}{{{K}_{1}}} \right]}^{-1}}\]
Answer» C. \[\frac{1}{2{{K}_{1}}}+\frac{1}{{{K}_{2}}}\]

Discussion

1184.	A 5 m long aluminium wire (\[Y=7\times {{10}^{10}}N/{{m}^{2}})\] of diameter 3 mm supports a 40 kg mass. In order to have the same elongation in a copper wire \[(Y=12\times {{10}^{10}}N/{{m}^{2}})\] of the same length under the same weight, the diameter should now be, in mm. [AMU 2000]
A.	1.75
B.	1.5
C.	2.5
D.	5.0
Answer» D. 5.0

Discussion

1185.	A mass m performs oscillations of period T when hanged by spring of force constant K. If spring is cut in two parts and arranged in parallel and same mass is oscillated by them, then the new time period will be [CPMT 1995; RPET 1997; RPMT 2003]
A.	2T
B.	T
C.	\[\frac{T}{\sqrt{2}}\]
D.	\[\frac{T}{2}\]
Answer» E.

Discussion

1186.	Two capillaries made of the same material with radii \[{{r}_{1}}=1mm\] and \[{{r}_{2}}=2mm\]. The rise of the liquid in one capillary (\[{{r}_{1}}=mm\]) is 30 cm, then the rise in the other will be [MP PET 1991]
A.	7.5 cm
B.	60 cm
C.	15 cm
D.	120 cm
Answer» D. 120 cm

Discussion

1187.	Find the frequency of minimum distance between compression & rarefaction of a wire. If the length of the wire is 1m & velocity of sound in air is 360 m/s [CPMT 2003]
A.	90 sec?1
B.	180s?1
C.	120 sec?1
D.	360 sec?1
Answer» B. 180s?1

Discussion

1188.	Assertion : Magnetic moment of an atom is due to both, the orbital motion and spin motion of every electron. Reason : A charged particle produces a magnetic field.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» D. If the assertion and reason both are false.

Discussion

1189.	In Fresnel's biprism experiment the width of 10 fringes is 2cm which are formed at a distance of 2 meter from the slit. If the wavelength of light is \[5100\overset{o}{\mathop{A}}\,\] then the distance between two coherent sources will be
A.	\[5.1\times {{10}^{-4}}m\]
B.	\[5.1\times {{10}^{4}}m\]
C.	\[5.1\times {{10}^{-4}}mm\]
D.	\[10.1\times {{10}^{-4}}cm\]
Answer» B. \[5.1\times {{10}^{4}}m\]

Discussion

1190.	The correct relation is [RPMT 2002]
A.	\[r=\frac{2T\,\cos \theta }{hdg}\]
B.	\[r=\frac{hdg}{2T\,\cos \theta }\]
C.	\[r=\frac{2T\,dgh}{\cos \theta }\]
D.	\[r=\frac{T\cos \theta }{2hdg}\]
Answer» B. \[r=\frac{hdg}{2T\,\cos \theta }\]

Discussion

1191.	Find the maximum velocity for skidding for a car moved on a circular track of radius 100 m. The coefficient of friction between the road and tyre is 0.2 [CPMT 1996; Pb. PMT 2001]
A.	0.14 m/s
B.	140 m/s
C.	1.4 km/s
D.	14 m/s
Answer» E.

Discussion

1192.	A block of mass 1 kg is pulled along the curve path ACB by a tangential force as shown in figure. The work done by the frictional force when the block moves from A to B is
A.	5 J
B.	10 J
C.	20 J
D.	None of these
Answer» D. None of these

Discussion

1193.	White light used to illuminate the two slits in Young's double slit experiment. The separation between the slits is d and the distance between the screen and the slit is D(>>d). At a point on the screen in front of one of the slits, certain wave- lengths are missing. The missing wavelengths are
A.	\[\lambda =\frac{{{d}^{2}}}{(2n+1)D}\]
B.	\[\lambda =\frac{(2n+1){{d}^{2}}}{D}\]
C.	\[\lambda =\frac{{{d}^{2}}}{(n+1)D}\]
D.	\[\lambda =\frac{(n+1)D}{{{d}^{2}}}\]
Answer» B. \[\lambda =\frac{(2n+1){{d}^{2}}}{D}\]

Discussion

1194.	A ray is incident at an angle of \[{{20}^{o}}\] to a plane mirror as shown in figure. If mirror is rotated by \[{{10}^{o}}\] in ACW direction and incident ray is rotated by \[{{10}^{o}}\] in CW direction then the reflected ray will be rotated by
A.	\[{{30}^{o}},\,CW\]
B.	\[{{10}^{o}},\,ACW\]
C.	\[{{30}^{o}},\,ACW\]
D.	\[{{10}^{o}},\,CW\]
Answer» D. \[{{10}^{o}},\,CW\]

Discussion

1195.	In the figure shown, a thick plano convex lens is silvered at both the surfaces. A point source of light 'S' is inside the lens. The radius of curvature of the spherical curved surface is (8/3) cm and the distance 'S' from the curved surface is 2 cm. If the images formed due to direct reflections from the plane and curved surface coincide, then find the thickness of the lens in cm.
A.	5
B.	7
C.	3
D.	8
Answer» D. 8

Discussion

1196.	Tube A has both ends open while tube B has one end closed, otherwise they are identical. The ratio of fundamental frequency of tube A and B is
A.	1 : 2
B.	1 : 4
C.	0.0840277777777778
D.	0.167361111111111
Answer» D. 0.167361111111111

Discussion

1197.	Assertion : The flash of lightening is seen before the sound of thunder is heard. Reason : Speed of sound is greater than speed of light [AIIMS 2002]
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» D. If the assertion and reason both are false.

Discussion

1198.	Assertion : Speed of wave \[=\frac{Wave\ length}{Time\ period}\] Reason : Wavelength is the distance between two nearest particles in phase. [AIIMS 2002]
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» C. If assertion is true but reason is false.

Discussion

1199.	Assertion : In the following circuit emf is 2V and internal resistance of the cell is 1 W and R = 1W, then reading of the voltmeter is 1V. Reason : \[V=E-ir\] where E = 2V, \[i=\frac{2}{2}=1A\] and R = 1 W [AIIMS 1995]
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion.

Discussion

1200.	Assertion : When a beetle moves along the sand with in a few tens of centimeters of a sand scorpion the scorpion immediately turn towards the beetle and dashes to it Reason : When a beetle disturbs the sand, it sends pulses along the sands surface one set of pulses is longitudinal while other set is transverse. [AIIMS 2003]
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion.

Discussion

Explore topic-wise MCQs in Joint Entrance Exam - Main (JEE Main).

The outer sphere of a spherical air capacitor is earthed. For increasing its capacitance [MP PET 1991]

Weight of a body is maximum at [AFMC 2001]

The unit of surface tension in SI system is [MP PMT 1984; AFMC 1986; CPMT 1985, 87; CBSE PMT 1993; KCET 1999; DCE 2000, 01]

A radioactive nucleus A with a half-life T, decays into a nucleus B. At \[t=0,\]there is no nucleus B. At some time t, the ratio of the number of B to that of A is 0.3. Then, t is given by

Velocity at mean position of a particle executing S.H.M. is v, they velocity of the particle at a distance equal to half of the amplitude [RPMT 2001]

If the binding energy per nucleon in \[L{{i}^{7}}\]and \[H{{e}^{4}}\] nuclei are respectively 5.60 MeV and 7.06 MeV, then energy of reaction \[L{{i}^{7}}+p\to 2{{\ }_{2}}H{{e}^{4}}\] is

A wheel having moment of inertia \[2\,kg-{{m}^{2}}\] about its vertical axis, rotates at the rate of 60 rpm about this axis. The torque which can stop the wheel's rotation in one minute would be

A projectile thrown with a speed \[v\] at an angle \[\theta \] has a range \[R\] on the surface of earth. For same \[v\] and \[\theta \], its range on the surface of moon will be

Sound waves of wavelength greater than that of audible sound are called [KCET 1999]

Which of the following do not require medium for transmission [RPMT 2000]

The work done in blowing a soap bubble of radius r of the solution of surface tension T will be [DPMT 1999; MP PMT 2003]

Electron volt is a unit of [MP PMT 2001]

A sphere of mass m, moving with velocity V, enters a hanging bag of sand and stops. If the mass of the bag is M and it is raised by height h, then the velocity of the sphere was [MP PET 1997]

Point masses 1, 2, 3 and 4 kg are lying at the points (0,0,0), (2,0,0), (0,3,0) and (-2, -2,0) respectively. The moment of inertia of this system about X-axis will be

A bird is sitting in a large closed cage which is placed on a spring balance. It records a weight of 25 N. The bird (mass m = 0.5 kg) flies upward in the cage with an acceleration of \[2\,m/{{s}^{2}}\]. The spring balance will now record a weight of [MP PMT 1999]

If the length of a wire is reduced to half, then it can hold the ......... load

When the number of turns in a coil is doubled without any change in the length of the coil, its self inductance becomes [MP PMT 1986; CBSE PMT 1992; Pb PET 2000]

Water is used to cool radiators of engines, because

Two spheres made of same substance have diameters in the ratio 1 : 2. Their thermal capacities are in the ratio of

At atmospheric pressure, the water boils at \[100{}^\circ C\]. If pressure is reduced, it will boil at

The SI unit of mechanical equivalent of heat is

A body of mass \[m\] moves in a circular path with uniform angular velocity. The motion of the body has constant [MP PET 2003]

A body of mass 10 kg is dropped to the ground from a height of 10 metres. The work done by the gravitational force is \[(g=9.8\,m/{{\sec }^{2}})\] [SCRA 1994]

Work done in splitting a drop of water of 1 mm radius into 106 droplets is (Surface tension of water \[=72\times {{10}^{-3}}J/{{m}^{2}})\] [MP PET/PMT 1988; CPMT 1989; RPET 2001]

Assertion : Under given conditions of pressure and temperature, sound travels faster in a monoatomic gas than in diatomic gas. Reason : Opposition for wave to travel is more in diatomic gas than monoatomic gas.

Assertion : The speed of sound in solids is maximum though their density is large. Reason : The coefficient of elasticity of solid is large.

Assertion : On a rainy day sound travel slower than on a dry day. Reason : When moisture is present in air the density of air increases.

An electron makes a transition from orbit n = 4 to the orbit n = 2 of a hydrogen atom. The wave number of the emitted radiations (R = Rydberg's constant) will be

According to Bohr's model, the radius of the second orbit of helium atom is

The ionisation potential of hydrogen atom is 13.6 volt. The energy required to remove an electron in the n = 2 state of the hydrogen atom is

If a watch with a wound spring is taken on to the moon, it [AFMC 1993]

What will be the force constant of the spring system shown in the figure [RPET 1996; Kerala (Med./ Engg.) 2005]

A 5 m long aluminium wire (\[Y=7\times {{10}^{10}}N/{{m}^{2}})\] of diameter 3 mm supports a 40 kg mass. In order to have the same elongation in a copper wire \[(Y=12\times {{10}^{10}}N/{{m}^{2}})\] of the same length under the same weight, the diameter should now be, in mm. [AMU 2000]

A mass m performs oscillations of period T when hanged by spring of force constant K. If spring is cut in two parts and arranged in parallel and same mass is oscillated by them, then the new time period will be [CPMT 1995; RPET 1997; RPMT 2003]

Two capillaries made of the same material with radii \[{{r}_{1}}=1mm\] and \[{{r}_{2}}=2mm\]. The rise of the liquid in one capillary (\[{{r}_{1}}=mm\]) is 30 cm, then the rise in the other will be [MP PET 1991]

Find the frequency of minimum distance between compression & rarefaction of a wire. If the length of the wire is 1m & velocity of sound in air is 360 m/s [CPMT 2003]

Assertion : Magnetic moment of an atom is due to both, the orbital motion and spin motion of every electron. Reason : A charged particle produces a magnetic field.

In Fresnel's biprism experiment the width of 10 fringes is 2cm which are formed at a distance of 2 meter from the slit. If the wavelength of light is \[5100\overset{o}{\mathop{A}}\,\] then the distance between two coherent sources will be

The correct relation is [RPMT 2002]

Find the maximum velocity for skidding for a car moved on a circular track of radius 100 m. The coefficient of friction between the road and tyre is 0.2 [CPMT 1996; Pb. PMT 2001]

A block of mass 1 kg is pulled along the curve path ACB by a tangential force as shown in figure. The work done by the frictional force when the block moves from A to B is

White light used to illuminate the two slits in Young's double slit experiment. The separation between the slits is d and the distance between the screen and the slit is D(>>d). At a point on the screen in front of one of the slits, certain wave- lengths are missing. The missing wavelengths are

A ray is incident at an angle of \[{{20}^{o}}\] to a plane mirror as shown in figure. If mirror is rotated by \[{{10}^{o}}\] in ACW direction and incident ray is rotated by \[{{10}^{o}}\] in CW direction then the reflected ray will be rotated by

Tube A has both ends open while tube B has one end closed, otherwise they are identical. The ratio of fundamental frequency of tube A and B is

Assertion : The flash of lightening is seen before the sound of thunder is heard. Reason : Speed of sound is greater than speed of light [AIIMS 2002]

Assertion : Speed of wave \[=\frac{Wave\ length}{Time\ period}\] Reason : Wavelength is the distance between two nearest particles in phase. [AIIMS 2002]

Assertion : In the following circuit emf is 2V and internal resistance of the cell is 1 W and R = 1W, then reading of the voltmeter is 1V. Reason : \[V=E-ir\] where E = 2V, \[i=\frac{2}{2}=1A\] and R = 1 W [AIIMS 1995]