50278 + Interview Questions in Physics Page 112 InterviewSolution

5551.	if velocity is cons†an t then speed will also cons†an t.justif
Answer» if velocity is cons†an t then speed will also cons†an t.justif

Discussion

5552.	Which of the following is incorrect about the electromagnetic waves?
Answer» Which of the following is incorrect about the electromagnetic waves?

Discussion

5553.	The temperature θ at the junction of two insulating sheets, having thermal resistances R1 and R2 as well as bottom and top temperatures θ1 and θ2 (as shown in figure) is given by :
Answer» The temperature $θ$ at the junction of two insulating sheets, having thermal resistances $R_{1}$ and $R_{2}$ as well as bottom and top temperatures $θ_{1}$ and $θ_{2}$ (as shown in figure) is given by :

Discussion

5554.	ntDefinition for Avogadro's hypothesisn
Answer» ntDefinition for Avogadro's hypothesisn

Discussion

5555.	A dimensionless quantity ______.
Answer» A dimensionless quantity ______.

Discussion

5556.	11. A battery is connected between two pointsA and B the circumference of a uniform conductingring of radius r and resistance R. One o the arcsAB of the ring subtends an angle q at the centre.The value of the magneticc inductionat the centre due to the current in the ring is8B(A) zero, only if q = 180^° (B) zero for all values of(C) proportional to 2(180(D) inversely proportional to rSol4
Answer» 11. A battery is connected between two pointsA and B the circumference of a uniform conductingring of radius r and resistance R. One o the arcsAB of the ring subtends an angle q at the centre.The value of the magneticc inductionat the centre due to the current in the ring is8B(A) zero, only if q = 180^° (B) zero for all values of(C) proportional to 2(180(D) inversely proportional to rSol4

Discussion

5557.	Two concentric spherical conduting shells of radius R_1 and R_{2 } (R_1>R_2) are having uniformly distributed charges Q_1 and Q_2 respectively. the total energy of the system is
Answer» Two concentric spherical conduting shells of radius R_1 and R_{2 } (R_1>R_2) are having uniformly distributed charges Q_1 and Q_2 respectively. the total energy of the system is

Discussion

5558.	When the switch is closed, the net charge which flows from point A to B is
Answer» When the switch is closed, the net charge which flows from point A to B is

Discussion

5559.	The ammeter that is connected in series must not produce a noticeable change in the current in the branch. Hence it’s resistance should best be
Answer» The ammeter that is connected in series must not produce a noticeable change in the current in the branch. Hence it’s resistance should best be

Discussion

5560.	If the vectors 3→p+→q,5→p−3→q and 2→p+→q,4→p−2→q are pairs of mutually perpendicular vectors, then the angle between vectors →p and →q is
Answer» If the vectors $3 \to p + \to q, 5 \to p - 3 \to q$ and $2 \to p + \to q, 4 \to p - 2 \to q$ are pairs of mutually perpendicular vectors, then the angle between vectors $\to p$ and $\to q$ is

Discussion

5561.	A system is shown in the figure. Find the moment of inertia about an axis passing through its COM and perpendicular to the plane. (Assume masses are connected with light inextensible strings)
Answer» A system is shown in the figure. Find the moment of inertia about an axis passing through its $C O M$ and perpendicular to the plane. (Assume masses are connected with light inextensible strings)

Discussion

5562.	Two mutually perpendicular infinite wires along x-axis and y-axis carry charge densities λ1 and λ2. The electric line on force at P is along the line y=1√3x, where P is also a point lying on the same line, then find λ2λ1.
Answer» Two mutually perpendicular infinite wires along $x$ -axis and $y$ -axis carry charge densities $λ_{1} and λ_{2}$ . The electric line on force at $P$ is along the line $y = \frac{1}{\sqrt{3}} x$ , where $P$ is also a point lying on the same line, then find $\frac{λ_{2}}{λ_{1}}$ .

Discussion

5563.	Two conductors of the same shape and size. one of Copper and the other of aluminium ( less conducting) are placed in an uniform electric field. The charge induced in aluminium A) will be less than in copper B) will be more than in copper C) will be equal to that of copper
Answer» Two conductors of the same shape and size. one of Copper and the other of aluminium ( less conducting) are placed in an uniform electric field. The charge induced in aluminium A) will be less than in copper B) will be more than in copper C) will be equal to that of copper

Discussion

5564.	The speed versus time graph, for a particle, is shown in the figure. The distance travelled (in m) by the particle during the time interval t=0 to t=5 sec will be
Answer» The speed versus time graph, for a particle, is shown in the figure. The distance travelled (in $m$ ) by the particle during the time interval $t = 0 to t = 5 sec$ will be

Discussion

5565.	A wheel of radius r rolls without slipping on a horizontal surface shwon below. If the velocity of point P is 10ms in the horizontal direction, the magnitude of velocity of point Q (inms) is
Answer» A wheel of radius r rolls without slipping on a horizontal surface shwon below. If the velocity of point P is $10 \frac{m}{s}$ in the horizontal direction, the magnitude of velocity of point Q $(i n \frac{m}{s})$ is

Discussion

5566.	if the earth were to suddenly contract to 1/n of its present radius without any change in its mass the duration of new day will be
Answer» if the earth were to suddenly contract to 1/n of its present radius without any change in its mass the duration of new day will be

Discussion

5567.	The de-Broglie wavelength of an electron in the first Bohr orbit of circumference 2πr is
Answer» The de-Broglie wavelength of an electron in the first Bohr orbit of circumference $2 π r$ is

Discussion

5568.	Three slabs of same dimension having dielectric constant K1,K2 and K3 completely fills the space between the plates of a capacitor as shown in figure. If C is the initial capacitance of the capacitor, the new capacitance is?
Answer» Three slabs of same dimension having dielectric constant $K_{1}, K_{2}$ and $K_{3}$ completely fills the space between the plates of a capacitor as shown in figure. If $C$ is the initial capacitance of the capacitor, the new capacitance is?

Discussion

5569.	From a square plate of side 8 m, a circular disc of radius 2 m is removed as shown in the figure. The mass density of the square plate is 1 kg/m2. Find the center of mass of the remaining portion.
Answer» From a square plate of side $8 m$ , a circular disc of radius $2 m$ is removed as shown in the figure. The mass density of the square plate is $1 {kg/m}^{2}$ . Find the center of mass of the remaining portion.

Discussion

5570.	If f(x)=x∫13t1+t2dt, where x>1, then which of the following is/are correct
Answer» If $f (x) = x \int 1 \frac{3^{t}}{1 + t^{2}} d t$ , where $x > 1$ , then which of the following is/are correct

Discussion

5571.	Draw a neat and labelled diagram of an electric bell and describe it’s working.
Answer» Draw a neat and labelled diagram of an electric bell and describe it’s working.

Discussion

5572.	75.L and C are connected in parallel to an AC source . The current through the inductor is 1.6A and the current through the capacitor is 0.4A the the current drawn from the source i
Answer» 75.L and C are connected in parallel to an AC source . The current through the inductor is 1.6A and the current through the capacitor is 0.4A the the current drawn from the source i

Discussion

5573.	What is Static State?
Answer» What is Static State?

Discussion

5574.	Two particles having position vectors →r1=(3^i+5^j) m and →r2=(−5^i+3^j) m are moving with velocities →v1=(4^i−4^j) ms−1 and →v2=(a^i−3^j) ms−1. If they collide after 2 s, the value of the constant 'a' is
Answer» Two particles having position vectors $_{1} = (3^i + 5^j) m$ and $_{2} = (- 5^i + 3^j) m$ are moving with velocities $_{1} = (4^i - 4^j) {ms}^{- 1}$ and $_{2} = (a^i - 3^j) {ms}^{- 1}$ . If they collide after $2 s$ , the value of the constant ' $a$ ' is

Discussion

5575.	3. Limx-0 [tanx]
Answer» 3. Limx-0 [tanx]

Discussion

5576.	Nuclei of a radioactive element is produced at constant rate α and they decay with decay constant λ. At t=0, the number of nuclei is 0. The number of active nuclei at time t is
Answer» Nuclei of a radioactive element is produced at constant rate $α$ and they decay with decay constant $λ$ . At $t = 0$ , the number of nuclei is 0. The number of active nuclei at time $t$ is

Discussion

5577.	73. A uniform flexible chain of mass m and lengthhangs in equilibrium over a smooth horizontal pin ofnegligible diameter. One end of the chain is given asmall vertical displacement so that the chain slipsover the pin. The speed of chain when it leaves pin isgl2
Answer» 73. A uniform flexible chain of mass m and lengthhangs in equilibrium over a smooth horizontal pin ofnegligible diameter. One end of the chain is given asmall vertical displacement so that the chain slipsover the pin. The speed of chain when it leaves pin isgl2

Discussion

5578.	The kinetic energy of a particle moving along a circle of radius R depends on distance (𝑠) as K=As2 where A is a constant.The speed of the particle around the circle is
Answer» The kinetic energy of a particle moving along a circle of radius $R$ depends on distance (𝑠) as $K = A s^{2}$ where $A$ is a constant. The speed of the particle around the circle is

Discussion

5579.	Find the speed of sound in a mixture of 1 mole of He and 2 mole of O2 at 27∘ C.
Answer» Find the speed of sound in a mixture of 1 mole of $H e$ and 2 mole of $O_{2}$ at $27^{\circ} C$ .

Discussion

5580.	Which of the following graphs shows the variation of magnetic induction B with distance r from a long wire carrying current [NCERT 1984; MNR 1998; MP PMT]
Answer» Which of the following graphs shows the variation of magnetic induction B with distance r from a long wire carrying current [NCERT 1984; MNR 1998; MP PMT]

5580.

Which of the following graphs shows the variation of magnetic induction B with distance r from a long wire carrying current [NCERT 1984; MNR 1998; MP PMT]

Answer»

Which of the following graphs shows the variation of magnetic induction B with distance r from a long wire carrying current

[NCERT 1984; MNR 1998; MP PMT]

Discussion

5581.	A great physicist of this century (P.A.M. Dirac) loved playing with numerical values of Fundamental constants of nature. This led him to an interesting observation. Dirac found that from the basic constants of atomic physics (c, e, mass of electron, mass of proton) and the gravitational constant G, he could arrive at a number with the dimension of time. Further, it was a very large number, its magnitude being close to the present estimate on the age of the universe (~15 billion years). From the table of fundamental constants in this book, try to see if you too can construct this number (or any other interesting number you can think of ). If its coincidence with the age of the universe were significant, what would this imply for the constancy of fundamental constants?
Answer» A great physicist of this century (P.A.M. Dirac) loved playing with numerical values of Fundamental constants of nature. This led him to an interesting observation. Dirac found that from the basic constants of atomic physics (c, e, mass of electron, mass of proton) and the gravitational constant G, he could arrive at a number with the dimension of time. Further, it was a very large number, its magnitude being close to the present estimate on the age of the universe (~15 billion years). From the table of fundamental constants in this book, try to see if you too can construct this number (or any other interesting number you can think of ). If its coincidence with the age of the universe were significant, what would this imply for the constancy of fundamental constants?

Discussion

5582.	A solid sphere of radius r=2 m is under a combination of rotational and translational motion as shown in figure. If acceleration of COM (O) is ao=2 m/s2 and acceleration of point A is aA=6 m/s2, then find angular acceleration α.
Answer» A solid sphere of radius $r = 2 m$ is under a combination of rotational and translational motion as shown in figure. If acceleration of COM $(O)$ is $a_{o} = 2 {m/s}^{2}$ and acceleration of point $A$ is $a_{A} = 6 {m/s}^{2}$ , then find angular acceleration $α$ .

Discussion

5583.	For real gases van der Waals' equation is written as (p+an2V2)(V−nb)=nRT where a and b are van der Waals' constants. Two sets of gases are(I) O2, CO2, H2 and He(II) CH4, O2 and H2The gases given in set-I in increasing order of b and gases given in set - II in decreasing order of a, are arranged below. Select the correct order from the following:
Answer» For real gases van der Waals' equation is written as $(p + \frac{a n^{2}}{V^{2}}) (V - n b) = n R T$ where a and b are van der Waals' constants. Two sets of gases are (I) $O_{2}, C O_{2}, H_{2} and H e$ (II) $C H_{4}, O_{2} and H_{2}$ The gases given in set-I in increasing order of b and gases given in set - II in decreasing order of a, are arranged below. Select the correct order from the following:

Discussion

5584.	Two balls of masses 1 kg and 2 kg are moving with speeds 2 m/s and 5 m/s as shown in figure. Find the impulse of deformation of 2 kg mass.
Answer» Two balls of masses $1 kg$ and $2 kg$ are moving with speeds $2 m/s$ and $5 m/s$ as shown in figure. Find the impulse of deformation of $2 kg$ mass.

Discussion

5585.	Plates of capacitor carries unequal charges as shown in figure, then which statement is wrong
Answer» Plates of capacitor carries unequal charges as shown in figure, then which statement is wrong

Discussion

5586.	can the vectors which are in the same or opposit direction called coplana
Answer» can the vectors which are in the same or opposit direction called coplana

Discussion

5587.	A given volume of air at 37∘C exerts a pressure of 870 mm of mercury. The temperature at which the pressure becomes 1740 mm of Hg is
Answer» A given volume of air at $37^{\circ} C$ exerts a pressure of $870 mm$ of mercury. The temperature at which the pressure becomes $1740 mm$ of $H g$ is

Discussion

5588.	There is a horizontal film of soap solution. A thread is placed on it, in the form of a loop. The film inside the loop is punctured and the thread becomes a circular loop of radius R. If the surface tension of the soap solution be T, then the tension in the thread will be,
Answer» There is a horizontal film of soap solution. A thread is placed on it, in the form of a loop. The film inside the loop is punctured and the thread becomes a circular loop of radius $R$ . If the surface tension of the soap solution be $T$ , then the tension in the thread will be,

Discussion

5589.	31. How to compare values of &quotb"(Van der Waals constant for volume correction) of different gases?
Answer» 31. How to compare values of "b"(Van der Waals constant for volume correction) of different gases?

Discussion

5590.	When an object is shot from bottom of an inclined plane at 60° it can travel distance x1. But when inclination is decreased to 30° if can travel x2 distance. Then x1:x2 will be
Answer» When an object is shot from bottom of an inclined plane at 60° it can travel distance x1. But when inclination is decreased to 30° if can travel x2 distance. Then x1:x2 will be

Discussion

5591.	if w1jouke work is done against gravitational attraction to carry 10 kg masd from the earth surface to infinity then the magnitude of workdone by gravtational attraction in bringing 20 kg mass from infinity to the cebtre now if w2=n × w1 fin
Answer» if w1jouke work is done against gravitational attraction to carry 10 kg masd from the earth surface to infinity then the magnitude of workdone by gravtational attraction in bringing 20 kg mass from infinity to the cebtre now if w2=n × w1 fin

Discussion

5592.	A 500 kg rocket can be accelerated at a constant rate from rest to 1800 km/h in 2 sec. What is the magnitude of the required net force?
Answer» A 500 kg rocket can be accelerated at a constant rate from rest to 1800 km/h in 2 sec. What is the magnitude of the required net force?

Discussion

5593.	28. A solid sphere of radius R is charged uniformly throughout the volume. At what distance from its surface, is the electric potential 1/4 of the potential at the centre?
Answer» 28. A solid sphere of radius R is charged uniformly throughout the volume. At what distance from its surface, is the electric potential 1/4 of the potential at the centre?

Discussion

5594.	The two nearest harmonics of a tube closed at one end and open at the other end are 220 Hz and 240 Hz respectively. What is the fundamental frequency of the system?
Answer» The two nearest harmonics of a tube closed at one end and open at the other end are $220 Hz$ and $240 Hz$ respectively. What is the fundamental frequency of the system?

Discussion

5595.	Determine the electric field strength vector if the potential of this field depends on x,y coordinates as V=10axy.
Answer» Determine the electric field strength vector if the potential of this field depends on $x, y$ coordinates as $V = 10 a x y$ .

Discussion

5596.	A parallel plate capacitor of capaci†an ce C is charged to a potential difference V and then the charging battery is disconnected .Now a charge Q is thrown on the positively charged plate . The new potential difference across the plates is 1)V -Q/2C 2)V +Q/2C 3)V -Q/C 4)V +Q/
Answer» A parallel plate capacitor of capaci†an ce C is charged to a potential difference V and then the charging battery is disconnected .Now a charge Q is thrown on the positively charged plate . The new potential difference across the plates is 1)V -Q/2C 2)V +Q/2C 3)V -Q/C 4)V +Q/

Discussion

5597.	A wall of thickness 0.6 m has a normal area 1.5 m2 and is made up of a material of thermal conductivity 0.4 W/mK. The temperature difference between the two sides is 800∘C.. Find the thermal resistance of the wall.
Answer» A wall of thickness $0.6 m$ has a normal area $1.5 m^{2}$ and is made up of a material of thermal conductivity $0.4 W/mK$ . The temperature difference between the two sides is $800^{\circ} C .$ . Find the thermal resistance of the wall.

Discussion

5598.	68.A dipole lies on the x axis with the positive charge +q at x=+d/2 and negative charge -quality ar x=-d/2. Find the net flux through the yz plane midway between the charges.
Answer» 68.A dipole lies on the x axis with the positive charge +q at x=+d/2 and negative charge -quality ar x=-d/2. Find the net flux through the yz plane midway between the charges.

Discussion

5599.	If the linear charge density of a rod of length 3 m varies as λ=(2+x) Cm, where x is the distance from one end of the rod, then find the total charge on the rod.
Answer» If the linear charge density of a rod of length $3 m$ varies as $λ = (2 + x) \frac{C}{m}$ , where $x$ is the distance from one end of the rod, then find the total charge on the rod.

Discussion

5600.	What is the maximum value upto which static friction can adjust itself ?
Answer» What is the maximum value upto which static friction can adjust itself ?

Discussion

Explore topic-wise InterviewSolutions in .

if velocity is cons†an t then speed will also cons†an t.justif

Which of the following is incorrect about the electromagnetic waves?

The temperature θ at the junction of two insulating sheets, having thermal resistances R1 and R2 as well as bottom and top temperatures θ1 and θ2 (as shown in figure) is given by :

ntDefinition for Avogadro's hypothesisn

A dimensionless quantity ______.

Two concentric spherical conduting shells of radius R_1 and R_{2 } (R_1>R_2) are having uniformly distributed charges Q_1 and Q_2 respectively. the total energy of the system is

When the switch is closed, the net charge which flows from point A to B is

The ammeter that is connected in series must not produce a noticeable change in the current in the branch. Hence it’s resistance should best be

If the vectors 3→p+→q,5→p−3→q and 2→p+→q,4→p−2→q are pairs of mutually perpendicular vectors, then the angle between vectors →p and →q is

A system is shown in the figure. Find the moment of inertia about an axis passing through its COM and perpendicular to the plane. (Assume masses are connected with light inextensible strings)

Two mutually perpendicular infinite wires along x-axis and y-axis carry charge densities λ1 and λ2. The electric line on force at P is along the line y=1√3x, where P is also a point lying on the same line, then find λ2λ1.

Two conductors of the same shape and size. one of Copper and the other of aluminium ( less conducting) are placed in an uniform electric field. The charge induced in aluminium A) will be less than in copper B) will be more than in copper C) will be equal to that of copper

The speed versus time graph, for a particle, is shown in the figure. The distance travelled (in m) by the particle during the time interval t=0 to t=5 sec will be

A wheel of radius r rolls without slipping on a horizontal surface shwon below. If the velocity of point P is 10ms in the horizontal direction, the magnitude of velocity of point Q (inms) is

if the earth were to suddenly contract to 1/n of its present radius without any change in its mass the duration of new day will be

The de-Broglie wavelength of an electron in the first Bohr orbit of circumference 2πr is

Three slabs of same dimension having dielectric constant K1,K2 and K3 completely fills the space between the plates of a capacitor as shown in figure. If C is the initial capacitance of the capacitor, the new capacitance is?

From a square plate of side 8 m, a circular disc of radius 2 m is removed as shown in the figure. The mass density of the square plate is 1 kg/m2. Find the center of mass of the remaining portion.

If f(x)=x∫13t1+t2dt, where x&gt;1, then which of the following is/are correct

Draw a neat and labelled diagram of an electric bell and describe it’s working.

75.L and C are connected in parallel to an AC source . The current through the inductor is 1.6A and the current through the capacitor is 0.4A the the current drawn from the source i

What is Static State?

Two particles having position vectors →r1=(3^i+5^j) m and →r2=(−5^i+3^j) m are moving with velocities →v1=(4^i−4^j) ms−1 and →v2=(a^i−3^j) ms−1. If they collide after 2 s, the value of the constant 'a' is

3. Limx-0 [tanx]

Nuclei of a radioactive element is produced at constant rate α and they decay with decay constant λ. At t=0, the number of nuclei is 0. The number of active nuclei at time t is

73. A uniform flexible chain of mass m and lengthhangs in equilibrium over a smooth horizontal pin ofnegligible diameter. One end of the chain is given asmall vertical displacement so that the chain slipsover the pin. The speed of chain when it leaves pin isgl2

The kinetic energy of a particle moving along a circle of radius R depends on distance (𝑠) as K=As2 where A is a constant.The speed of the particle around the circle is

Find the speed of sound in a mixture of 1 mole of He and 2 mole of O2 at 27∘ C.

Which of the following graphs shows the variation of magnetic induction B with distance r from a long wire carrying current [NCERT 1984; MNR 1998; MP PMT]

A solid sphere of radius r=2 m is under a combination of rotational and translational motion as shown in figure. If acceleration of COM (O) is ao=2 m/s2 and acceleration of point A is aA=6 m/s2, then find angular acceleration α.

Two balls of masses 1 kg and 2 kg are moving with speeds 2 m/s and 5 m/s as shown in figure. Find the impulse of deformation of 2 kg mass.

Plates of capacitor carries unequal charges as shown in figure, then which statement is wrong

can the vectors which are in the same or opposit direction called coplana

A given volume of air at 37∘C exerts a pressure of 870 mm of mercury. The temperature at which the pressure becomes 1740 mm of Hg is

There is a horizontal film of soap solution. A thread is placed on it, in the form of a loop. The film inside the loop is punctured and the thread becomes a circular loop of radius R. If the surface tension of the soap solution be T, then the tension in the thread will be,

31. How to compare values of &quotb"(Van der Waals constant for volume correction) of different gases?

When an object is shot from bottom of an inclined plane at 60° it can travel distance x1. But when inclination is decreased to 30° if can travel x2 distance. Then x1:x2 will be

if w1jouke work is done against gravitational attraction to carry 10 kg masd from the earth surface to infinity then the magnitude of workdone by gravtational attraction in bringing 20 kg mass from infinity to the cebtre now if w2=n × w1 fin

A 500 kg rocket can be accelerated at a constant rate from rest to 1800 km/h in 2 sec. What is the magnitude of the required net force?

28. A solid sphere of radius R is charged uniformly throughout the volume. At what distance from its surface, is the electric potential 1/4 of the potential at the centre?

The two nearest harmonics of a tube closed at one end and open at the other end are 220 Hz and 240 Hz respectively. What is the fundamental frequency of the system?

Determine the electric field strength vector if the potential of this field depends on x,y coordinates as V=10axy.

A parallel plate capacitor of capaci†an ce C is charged to a potential difference V and then the charging battery is disconnected .Now a charge Q is thrown on the positively charged plate . The new potential difference across the plates is 1)V -Q/2C 2)V +Q/2C 3)V -Q/C 4)V +Q/

A wall of thickness 0.6 m has a normal area 1.5 m2 and is made up of a material of thermal conductivity 0.4 W/mK. The temperature difference between the two sides is 800∘C.. Find the thermal resistance of the wall.

68.A dipole lies on the x axis with the positive charge +q at x=+d/2 and negative charge -quality ar x=-d/2. Find the net flux through the yz plane midway between the charges.

If the linear charge density of a rod of length 3 m varies as λ=(2+x) Cm, where x is the distance from one end of the rod, then find the total charge on the rod.

What is the maximum value upto which static friction can adjust itself ?

If f(x)=x∫13t1+t2dt, where x>1, then which of the following is/are correct