12583 + Mcqs in Physics Page 204 McqOptions

10151.	In frequency modulation [Kerala PMT 2005]
A.	The amplitude of modulated wave varies as frequency of carrier wave
B.	The frequency of modulated wave varies as amplitude of modulating wave
C.	The amplitude of modulated wave varies as amplitude of carrier wave
D.	The frequency of modulated wave varies as frequency of modulating wave
E.	(e) The frequency of modulated wave varies as frequency of carrier wave
Answer» C. The amplitude of modulated wave varies as amplitude of carrier wave

Discussion

10152.	An object of mass 3m splits into three equal fragments. Two fragments have velocities \[v\hat{j}\] and \[v\hat{i}\]. The velocity of the third fragment is [UPSEAT 2004]
A.	\[v(\hat{j}-\hat{i})\]
B.	\[v(\hat{i}-\hat{j})\]
C.	\[-v(\hat{i}+\hat{j})\]
D.	\[\frac{v(\hat{i}+\hat{j})}{\sqrt{2}}\]
Answer» D. \[\frac{v(\hat{i}+\hat{j})}{\sqrt{2}}\]

Discussion

10153.	The plates of parallel plate capacitor are charged upto\[100\ V\]. A\[2mm\] thick plate is inserted between the plates. Then to maintain the same potential difference, the distance between the plates is increased by\[1.6\ mm\]. The dielectric constant of the plate is [MP PMT 1991]
A.	5
B.	1.25
C.	4
D.	2.5
Answer» B. 1.25

Discussion

10154.	Assertion : According to law of conservation of mechanical energy change in potential energy is equal and opposite to the change in kinetic energy. Reason : Mechanical energy is not a conserved quantity.
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

10155.	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

10156.	Assertion : By roughening the surface of a glass sheet its transparency can be reduced. Reason : Glass sheet with rough surface absorbs more light. [AIIMS 2005]
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

10157.	Assertion : The cloud in sky generally appear to be whitish. Reason : Diffraction due to cloud is efficient in equal measure at all wavelengths. [AIIMS 2005]
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

10158.	Assertion : Diamond glitters brilliantly. Reason : Diamond does not absorb sunlight. [AIIMS 2005]
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

10159.	In Millikan oil drop experiment, a charged drop of mass \[1.8\times {{10}^{-14}}kg\]is stationary between its plates. The distance between its plates is 0.90 cm and potential difference is 2.0 kilo volts. The number of electrons on the drop is [MP PMT 1994, 2003; MP PET 1997]
A.	500
B.	50
C.	5
D.	0
Answer» D. 0

Discussion

10160.	What is the area of the plates of a \[3F\] parallel plate capacitor, if the separation between the plates is \[5mm\] [AIIMS 1998; Pb. PET 2000; BHU 2002]
A.	\[1.694\times {{10}^{9}}{{m}^{2}}\]
B.	\[4.529\times {{10}^{9}}{{m}^{2}}\]
C.	\[9.281\times {{10}^{9}}\ {{m}^{2}}\]
D.	\[12.981\times {{10}^{9}}\ {{m}^{2}}\]
Answer» B. \[4.529\times {{10}^{9}}{{m}^{2}}\]

Discussion

10161.	An ideal gas at \[{{27}^{o}}C\] is compressed adiabatically to \[\frac{8}{27}\] of its original volume. If \[\gamma =\frac{5}{3}\], then the rise in temperature is [CPMT 1984; CBSE PMT 1999; DPMT 2000; BHU 2001; Pb. PET 2001; UPSEAT 2002, 03; KCET 2003;]
A.	450 K
B.	375 K
C.	225 K
D.	405 K
Answer» C. 225 K

Discussion

10162.	When hydrogen atom is in its first excited level, its radius is .... its ground state radius [CBSE PMT 1997]
A.	Half
B.	Same
C.	Twice
D.	Four times
Answer» C. Twice

Discussion

10163.	Assertion : A narrow pulse of light is sent through a medium. The pulse will retain its shape as it travels through the medium. Reason : A narrow pulse is made of harmonic waves with a large range of wavelengths.
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» F.

Discussion

10164.	Assertion : Simple harmonic motion is a uniform motion. Reason : Simple harmonic motion is the projection of uniform circular motion.
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» F.

Discussion

10165.	Assertion : All oscillatory motions are necessarily periodic motion but all periodic motion are not oscillatory. Reason : Simple pendulum is an example of oscillatory motion.
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

10166.	Assertion : The susceptibility of diamagnetic materials does not depend upon temperature. Reason : Every atom of a diamagnetic material is not a complete magnet in itself.
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

10167.	With the increase in principle quantum number, the energy difference between the two successive energy levels [RPET 2003]
A.	Increases
B.	Decreases
C.	Remains constant
D.	Sometimes increases and sometimes decreases
Answer» C. Remains constant

Discussion

10168.	The third line of Balmer series of an ion equivalent to hydrogen atom has wavelength of 108.5 nm. The ground state energy of an electron of this ion will be [RPET 1997]
A.	3.4 eV
B.	13.6 eV
C.	54.4 eV
D.	122.4 eV
Answer» D. 122.4 eV

Discussion

10169.	Assertion : Cyclotron does not accelerate electron. Reason : Mass of the electron is very small. [AIIMS 2000]
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

10170.	In the non-resonant circuit, what will be the nature of the circuit for frequencies higher than the resonant frequency [RPET 1996]
A.	Resistive
B.	Capacitive
C.	Inductive
D.	None of the above
Answer» C. Inductive

Discussion

10171.	The ratio of the largest to shortest wavelengths in Lyman series of hydrogen spectra is [EAMCET (Med.) 2000]
A.	\[\frac{25}{9}\]
B.	\[\frac{17}{6}\]
C.	\[\frac{9}{5}\]
D.	\[\frac{4}{3}\]
Answer» E.

Discussion

10172.	An electron moving in a circular orbit of radius r makes n rotation per second. The magnetic field produced at the centre has a magnitude of [KCET 2001; UPSEAT 2001, 02]
A.	\[\frac{{{\mu }_{0}}ne}{2r}\]
B.	\[\frac{{{\mu }_{0}}{{n}^{2}}e}{2r}\]
C.	\[\frac{{{\mu }_{0}}ne}{2\pi r}\]
D.	Zero
Answer» B. \[\frac{{{\mu }_{0}}{{n}^{2}}e}{2r}\]

Discussion

10173.	Assertion : Chock coil is preferred over a resistor to adjust current in an ac circuit. Reason : Power factor for inductance is zero.
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

10174.	In an ac circuit, peak value of voltage is 423 volts. Its effective voltage is [JIPMER 1997]
A.	400 volts
B.	323 volts
C.	300 volts
D.	340 volts
Answer» D. 340 volts

Discussion

10175.	A tuning fork produces waves in a medium. If the temperature of the medium changes, then which of the following will change [EAMCET (Med.) 1998; Pb. PMT 1999; MH CET 2001]
A.	Amplitude
B.	Frequency
C.	Wavelength
D.	Time-period
Answer» D. Time-period

Discussion

10176.	Assertion : The poles of magnet cannot be separated by breaking into two pieces. Reason : The magnetic moment will be reduced to half when a magnet is broken into two equal pieces. [SCRA 1994]
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

10177.	Assertion : Mass of ion is slightly differed from its element. Reason : Ion is formed, when some electrons are removed or added so mass changes.
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

10178.	Assertion : Soft steel can be made red hot by continued hammering on it, but hard steel cannot. Reason : Energy transfer in case of soft iron is large as in hard steel.
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

10179.	The primary winding of transformer has 500 turns whereas its secondary has 5000 turns. The primary is connected to an ac supply of 20 V, 50 Hz. The secondary will have an output of [CBSE PMT 1997; AIIMS 1999]
A.	200 V, 50 Hz
B.	2 V, 50 Hz
C.	200 V, 500 Hz
D.	2 V, 5 Hz
Answer» B. 2 V, 50 Hz

Discussion

10180.	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 [NCERT 1983; MP PET 2005]
A.	27.2 eV
B.	13.6eV
C.	6.8eV
D.	3.4eV
Answer» E.

Discussion

10181.	Assertion : For an oscillating simple pendulum, the tension in the string is maximum at the mean position and minimum at the extreme position. Reason : The velocity of oscillating bob in simple harmonic motion is maximum at the mean position.
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

10182.	Assertion : If the amplitude of a simple harmonic oscillator is doubled, its total energy becomes four times. Reason : The total energy is directly proportional to the square of amplitude of vibration of the harmonic oscillator.
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

10183.	When air is replaced by a dielectric medium of constant \[k\], the maximum force of attraction between two charges separated by a distance [CBSE PMT 1999]
A.	Decreases \[k\] times
B.	Remains unchanged
C.	Increases \[k\] times
D.	Increases \[{{k}^{-1}}\] times
Answer» B. Remains unchanged

Discussion

10184.	Two long parallel wires P and Q are both perpendicular to the plane of the paper with distance 5 m between them. If P and Q carry current of 2.5 amp and 5 amp respectively in the same direction, then the magnetic field at a point half way between the wires is [Kerala PMT 2005]
A.	\[\frac{\sqrt{3}{{\mu }_{0}}}{2\pi }\]
B.	\[\frac{{{\mu }_{0}}}{\pi }\]
C.	\[\frac{3{{\mu }_{0}}}{2\pi }\]
D.	\[\frac{{{\mu }_{0}}}{2\pi }\]
E.	(e) \[\frac{\sqrt{3}{{\mu }_{0}}}{\pi }\]
Answer» E. (e) \[\frac{\sqrt{3}{{\mu }_{0}}}{\pi }\]

Discussion

10185.	In Bohr's model of hydrogen atom, let PE represents potential energy and TE the total energy. In going to a higher level [KCET 1994]
A.	PE decreases, TE increases
B.	PE increases, TE increases
C.	PE decreases, TE decreases
D.	PE increases, TE decreases
Answer» C. PE decreases, TE decreases

Discussion

10186.	A medium can carry a longitudinal wave because it has the property of [KCET 1994]
A.	Mass
B.	Density
C.	Compressibility
D.	Elasticity
Answer» E.

Discussion

10187.	Assertion : In transistor common emitter mode as an amplifier is preferred over common base mode. Reason : In common emitter mode the input signal is connected in series with the voltage applied to the base emitter function.
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

10188.	The coefficient of thermal conductivity of copper is nine times that of steel. In the composite cylindrical bar shown in the figure. What will be the temperature at the junction of copper and steel [MP PMT 2000; BHU 2004]
A.	\[{{75}^{o}}C\]
B.	\[{{67}^{o}}C\]
C.	\[{{33}^{o}}C\]
D.	\[{{25}^{o}}C\]
Answer» B. \[{{67}^{o}}C\]

Discussion

10189.	Assertion : Cars and aeroplanes are streamlined. Reason : This is done to reduce the backward drag due to atmosphere.
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

10190.	Between the plates of a parallel plate condenser, a plate of thickness \[{{t}_{1}}\]and dielectric constant \[{{k}_{1}}\] is placed. In the rest of the space, there is another plate of thickness \[{{t}_{2}}\] and dielectric constant \[{{k}_{2}}\]. The potential difference across the condenser will be [MP PET 1993]
A.	\[\frac{Q}{A{{\varepsilon }_{0}}}\left( \frac{{{t}_{1}}}{{{k}_{1}}}+\frac{{{t}_{2}}}{{{k}_{2}}} \right)\]
B.	\[\frac{{{\varepsilon }_{0}}Q}{A}\left( \frac{{{t}_{1}}}{{{k}_{1}}}+\frac{{{t}_{2}}}{{{k}_{2}}} \right)\]
C.	\[\frac{Q}{A{{\varepsilon }_{0}}}\left( \frac{{{k}_{1}}}{{{t}_{1}}}+\frac{{{k}_{2}}}{{{t}_{2}}} \right)\]
D.	\[\frac{{{\varepsilon }_{0}}Q}{A}({{k}_{1}}{{t}_{1}}+{{k}_{2}}{{t}_{2}})\]
Answer» B. \[\frac{{{\varepsilon }_{0}}Q}{A}\left( \frac{{{t}_{1}}}{{{k}_{1}}}+\frac{{{t}_{2}}}{{{k}_{2}}} \right)\]

Discussion

10191.	Assertion : Two identical solid balls, one of ivory and the other of wet-clay are dropped from the same height on the floor. Both the balls will rise to same height after bouncing. Reason : Ivory and wet-clay have same elasticity.
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

10192.	Assertion : An electric bulb is first connected to a dc source and then to a ac source having the same brightness in both the cases. Reason : The peak value of voltage for an A.C. source is \[\sqrt{2}\]times the root mean square voltage.
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» F.

Discussion

10193.	Magnetic fields at two points on the axis of a circular coil at a distance of 0.05m and 0.2m from the centre are in the ratio 8 : 1. The radius of the coil is [KCET 2002]
A.	1.0 m
B.	0.1 m
C.	0.15 m
D.	0.2 m
Answer» C. 0.15 m

Discussion

10194.	If the angular speed of the earth is doubled, the value of acceleration due to gravity (g) at the north pole [EAMCET (Med.) 1995]
A.	Doubles
B.	Becomes half
C.	Remains same
D.	Becomes zero
Answer» D. Becomes zero

Discussion

10195.	An inductor L and a capacitor C are connected in the circuit as shown in the figure. The frequency of the power supply is equal to the resonant frequency of the circuit. Which ammeter will read zero ampere [DCE 2002]
A.	\[{{A}_{1}}\]
B.	\[{{A}_{2}}\]
C.	\[{{A}_{3}}\]
D.	None of these
Answer» D. None of these

Discussion

10196.	The mean electric energy density between the plates of a charged capacitor is (here \[q\]= charge on the capacitor and \[A\]= area of the capacitor plate) [MP PET 2002]
A.	\[\frac{{{q}^{2}}}{2{{\varepsilon }_{0}}{{A}^{2}}}\]
B.	\[\frac{q}{2{{\varepsilon }_{0}}{{A}^{2}}}\]
C.	\[\frac{{{q}^{2}}}{2{{\varepsilon }_{0}}A}\]
D.	None of the above
Answer» B. \[\frac{q}{2{{\varepsilon }_{0}}{{A}^{2}}}\]

Discussion

10197.	In a region of uniform magnetic induction \[B={{10}^{-2}}\,tesla\], a circular coil of radius 30 cm and resistance p2 ohm is rotated about an axis which is perpendicular to the direction of B and which forms a diameter of the coil. If the coil rotates at 200 rpm the amplitude of the alternating current induced in the coil is [CBSE PMT 1990]
A.	4p2 mA
B.	30 mA
C.	6 mA
D.	200 mA
Answer» D. 200 mA

Discussion

10198.	Assertion : The speed of a body can be negative. Reason : If the body is moving in the opposite direction of positive motion, then its speed is negative.
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

10199.	In a capacitor of capacitance \[20\mu \,F\], the distance between the plates is 2mm. If a dielectric slab of width 1mm and dielectric constant 2 is inserted between the plates, then the new capacitance is [BHU 2000]
A.	\[2\mu \,F\]
B.	\[15.5\mu \,F\]
C.	\[26.6\mu \,F\]
D.	\[32\mu \,F\]
Answer» D. \[32\mu \,F\]

Discussion

10200.	An oscillator is producing FM waves of frequency 2 kHz with a variation of 10 kHz. What is the modulating index [DCE 2004]
A.	0.20
B.	5.0
C.	0.67
D.	1.5
Answer» C. 0.67

Discussion

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

In frequency modulation [Kerala PMT 2005]

An object of mass 3m splits into three equal fragments. Two fragments have velocities \[v\hat{j}\] and \[v\hat{i}\]. The velocity of the third fragment is [UPSEAT 2004]

The plates of parallel plate capacitor are charged upto\[100\ V\]. A\[2mm\] thick plate is inserted between the plates. Then to maintain the same potential difference, the distance between the plates is increased by\[1.6\ mm\]. The dielectric constant of the plate is [MP PMT 1991]

Assertion : According to law of conservation of mechanical energy change in potential energy is equal and opposite to the change in kinetic energy. Reason : Mechanical energy is not a conserved quantity.

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

Assertion : By roughening the surface of a glass sheet its transparency can be reduced. Reason : Glass sheet with rough surface absorbs more light. [AIIMS 2005]

Assertion : The cloud in sky generally appear to be whitish. Reason : Diffraction due to cloud is efficient in equal measure at all wavelengths. [AIIMS 2005]

Assertion : Diamond glitters brilliantly. Reason : Diamond does not absorb sunlight. [AIIMS 2005]

In Millikan oil drop experiment, a charged drop of mass \[1.8\times {{10}^{-14}}kg\]is stationary between its plates. The distance between its plates is 0.90 cm and potential difference is 2.0 kilo volts. The number of electrons on the drop is [MP PMT 1994, 2003; MP PET 1997]

What is the area of the plates of a \[3F\] parallel plate capacitor, if the separation between the plates is \[5mm\] [AIIMS 1998; Pb. PET 2000; BHU 2002]

An ideal gas at \[{{27}^{o}}C\] is compressed adiabatically to \[\frac{8}{27}\] of its original volume. If \[\gamma =\frac{5}{3}\], then the rise in temperature is [CPMT 1984; CBSE PMT 1999; DPMT 2000; BHU 2001; Pb. PET 2001; UPSEAT 2002, 03; KCET 2003;]

When hydrogen atom is in its first excited level, its radius is .... its ground state radius [CBSE PMT 1997]

Assertion : A narrow pulse of light is sent through a medium. The pulse will retain its shape as it travels through the medium. Reason : A narrow pulse is made of harmonic waves with a large range of wavelengths.

Assertion : Simple harmonic motion is a uniform motion. Reason : Simple harmonic motion is the projection of uniform circular motion.

Assertion : All oscillatory motions are necessarily periodic motion but all periodic motion are not oscillatory. Reason : Simple pendulum is an example of oscillatory motion.

Assertion : The susceptibility of diamagnetic materials does not depend upon temperature. Reason : Every atom of a diamagnetic material is not a complete magnet in itself.

With the increase in principle quantum number, the energy difference between the two successive energy levels [RPET 2003]

The third line of Balmer series of an ion equivalent to hydrogen atom has wavelength of 108.5 nm. The ground state energy of an electron of this ion will be [RPET 1997]

Assertion : Cyclotron does not accelerate electron. Reason : Mass of the electron is very small. [AIIMS 2000]

In the non-resonant circuit, what will be the nature of the circuit for frequencies higher than the resonant frequency [RPET 1996]

The ratio of the largest to shortest wavelengths in Lyman series of hydrogen spectra is [EAMCET (Med.) 2000]

An electron moving in a circular orbit of radius r makes n rotation per second. The magnetic field produced at the centre has a magnitude of [KCET 2001; UPSEAT 2001, 02]

Assertion : Chock coil is preferred over a resistor to adjust current in an ac circuit. Reason : Power factor for inductance is zero.

In an ac circuit, peak value of voltage is 423 volts. Its effective voltage is [JIPMER 1997]

A tuning fork produces waves in a medium. If the temperature of the medium changes, then which of the following will change [EAMCET (Med.) 1998; Pb. PMT 1999; MH CET 2001]

Assertion : The poles of magnet cannot be separated by breaking into two pieces. Reason : The magnetic moment will be reduced to half when a magnet is broken into two equal pieces. [SCRA 1994]

Assertion : Mass of ion is slightly differed from its element. Reason : Ion is formed, when some electrons are removed or added so mass changes.

Assertion : Soft steel can be made red hot by continued hammering on it, but hard steel cannot. Reason : Energy transfer in case of soft iron is large as in hard steel.

The primary winding of transformer has 500 turns whereas its secondary has 5000 turns. The primary is connected to an ac supply of 20 V, 50 Hz. The secondary will have an output of [CBSE PMT 1997; AIIMS 1999]

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 [NCERT 1983; MP PET 2005]

Assertion : For an oscillating simple pendulum, the tension in the string is maximum at the mean position and minimum at the extreme position. Reason : The velocity of oscillating bob in simple harmonic motion is maximum at the mean position.

Assertion : If the amplitude of a simple harmonic oscillator is doubled, its total energy becomes four times. Reason : The total energy is directly proportional to the square of amplitude of vibration of the harmonic oscillator.

When air is replaced by a dielectric medium of constant \[k\], the maximum force of attraction between two charges separated by a distance [CBSE PMT 1999]

Two long parallel wires P and Q are both perpendicular to the plane of the paper with distance 5 m between them. If P and Q carry current of 2.5 amp and 5 amp respectively in the same direction, then the magnetic field at a point half way between the wires is [Kerala PMT 2005]

In Bohr's model of hydrogen atom, let PE represents potential energy and TE the total energy. In going to a higher level [KCET 1994]

A medium can carry a longitudinal wave because it has the property of [KCET 1994]

Assertion : In transistor common emitter mode as an amplifier is preferred over common base mode. Reason : In common emitter mode the input signal is connected in series with the voltage applied to the base emitter function.

The coefficient of thermal conductivity of copper is nine times that of steel. In the composite cylindrical bar shown in the figure. What will be the temperature at the junction of copper and steel [MP PMT 2000; BHU 2004]

Assertion : Cars and aeroplanes are streamlined. Reason : This is done to reduce the backward drag due to atmosphere.

Assertion : Two identical solid balls, one of ivory and the other of wet-clay are dropped from the same height on the floor. Both the balls will rise to same height after bouncing. Reason : Ivory and wet-clay have same elasticity.

Assertion : An electric bulb is first connected to a dc source and then to a ac source having the same brightness in both the cases. Reason : The peak value of voltage for an A.C. source is \[\sqrt{2}\]times the root mean square voltage.

Magnetic fields at two points on the axis of a circular coil at a distance of 0.05m and 0.2m from the centre are in the ratio 8 : 1. The radius of the coil is [KCET 2002]

If the angular speed of the earth is doubled, the value of acceleration due to gravity (g) at the north pole [EAMCET (Med.) 1995]

An inductor L and a capacitor C are connected in the circuit as shown in the figure. The frequency of the power supply is equal to the resonant frequency of the circuit. Which ammeter will read zero ampere [DCE 2002]

The mean electric energy density between the plates of a charged capacitor is (here \[q\]= charge on the capacitor and \[A\]= area of the capacitor plate) [MP PET 2002]

Assertion : The speed of a body can be negative. Reason : If the body is moving in the opposite direction of positive motion, then its speed is negative.

In a capacitor of capacitance \[20\mu \,F\], the distance between the plates is 2mm. If a dielectric slab of width 1mm and dielectric constant 2 is inserted between the plates, then the new capacitance is [BHU 2000]

An oscillator is producing FM waves of frequency 2 kHz with a variation of 10 kHz. What is the modulating index [DCE 2004]