50278 + Interview Questions in Physics

1.	A cylindrical tube open at both the ends has a fundamentaf requency of 390 Hz in air. If 1/4 -th of the tube is immersed vertically in water the fundamental frequency of air column is
Answer» A cylindrical tube open at both the ends has a fundamentaf requency of 390 Hz in air. If 1/4 -th of the tube is immersed vertically in water the fundamental frequency of air column is

Discussion

2.	Why is gravitational field intensity zero inside the spherical shell although constant in case of gravitational potential ?
Answer» Why is gravitational field intensity zero inside the spherical shell although constant in case of gravitational potential ?

Discussion

3.	46.The phase difference between current and voltage, when the freqeuency of applied emf is w + R/2L (w is resonance frequency) in a series LCR circuit is (a) pi/2 (b) pi/4 (c)pi/6 (d)0
Answer» 46.The phase difference between current and voltage, when the freqeuency of applied emf is w + R/2L (w is resonance frequency) in a series LCR circuit is (a) pi/2 (b) pi/4 (c)pi/6 (d)0

Discussion

4.	Force F=2i-3j+2k acting on a particle about the point O such that it's position vector r=i+k , then find the angle between the force and position vector and also find out the torque.
Answer» Force F=2i-3j+2k acting on a particle about the point O such that it's position vector r=i+k , then find the angle between the force and position vector and also find out the torque.

Discussion

5.	Nuclei of radioactive element A are produced at rate t2 at any time t. The element A has decay constant λ. Let N be the number of nuclei of element A at any time t. At time t=t0, dNdt is minimum. Then the number of nuclei of element A at time t=t0 is :
Answer» Nuclei of radioactive element $A$ are produced at rate $t^{2}$ at any time $t$ . The element $A$ has decay constant $λ$ . Let $N$ be the number of nuclei of element $A$ at any time $t$ . At time $t = t_{0}, \frac{d N}{d t}$ is minimum. Then the number of nuclei of element $A$ at time $t = t_{0}$ is :

Discussion

6.	A uniform wire is stretched uniformed by 0.5%.Its resistance change by
Answer» A uniform wire is stretched uniformed by 0.5%.Its resistance change by

Discussion

7.	In a projectile motion, velocity at maximum height is
Answer» In a projectile motion, velocity at maximum height is

Discussion

8.	A circuit A takes a current of 3 A at a power factor of 0.6 lagging when connected to a 115 V, 50 Hz supply. Another circuit B takes a current of 5 A at a power factor of 0.707 leading when connected to the same supply. If the two circuits are connected in series across a 230 V, 50 Hz supply, calculate the impedance of the circuit.
Answer» A circuit $A$ takes a current of $3 A$ at a power factor of $0.6$ lagging when connected to a $115 V, 50 Hz$ supply. Another circuit $B$ takes a current of $5 A$ at a power factor of $0.707$ leading when connected to the same supply. If the two circuits are connected in series across a $230 V, 50 Hz$ supply, calculate the impedance of the circuit.

Discussion

9.	Two bulbs, one of 200 Volts,60 Watts and the other of 200 Volts,100 Watts are connected in series to a 200 Volt supply. The power consumed will be
Answer» Two bulbs, one of $200 Volts, 60 Watts$ and the other of $200 Volts, 100 Watts$ are connected in series to a $200 Volt$ supply. The power consumed will be

Discussion

10.	if the length of the conductor is strected by 20 % , percentage of net resistance is ?
Answer» if the length of the conductor is strected by 20 % , percentage of net resistance is ?

Discussion

11.	The graph represents the s-t curve of a body moving in a straight line. At which moment 't' is the instantaneous velocity approximately equal to the average velocity over the first 't' seconds?
Answer» The graph represents the s-t curve of a body moving in a straight line. At which moment 't' is the instantaneous velocity approximately equal to the average velocity over the first 't' seconds?

11.

The graph represents the s-t curve of a body moving in a straight line. At which moment 't' is the instantaneous velocity approximately equal to the average velocity over the first 't' seconds?

Answer»

The graph represents the s-t curve of a body moving in a straight line. At which moment 't' is the instantaneous velocity approximately equal to the average velocity over the first 't' seconds?

Discussion

12.	A rabbit runs across a parking lot on which a set of coordinate axes has, strangely enough, been drawn. The coordinates (meters) of the rabbit's position as function of time t(seconds) are given by x(t)=−t22+5t+20 And y(t)=t2−10t+30 Find the velocity at time t = 15s.
Answer» A rabbit runs across a parking lot on which a set of coordinate axes has, strangely enough, been drawn. The coordinates (meters) of the rabbit's position as function of time t(seconds) are given by $x (t) = - \frac{t^{2}}{2} + 5 t + 20$ And $y (t) = t^{2} - 10 t + 30$ Find the velocity at time t = 15s.

12.

A rabbit runs across a parking lot on which a set of coordinate axes has, strangely enough, been drawn. The coordinates (meters) of the rabbit's position as function of time t(seconds) are given by x(t)=−t22+5t+20 And y(t)=t2−10t+30 Find the velocity at time t = 15s.

Answer»

A rabbit runs across a parking lot on which a set of coordinate axes has, strangely enough, been drawn.
The coordinates (meters) of the rabbit's position as function of time t(seconds) are given by

$x (t) = - \frac{t^{2}}{2} + 5 t + 20$
And $y (t) = t^{2} - 10 t + 30$

Find the velocity at time t = 15s.

Discussion

13.	In accordance with theBohr’s model, find the quantum number that characterises theearth’s revolution around the sun in an orbit of radius 1.5 ×1011 m with orbital speed 3 × 104 m/s.(Mass of earth = 6.0 × 1024 kg.)
Answer» In accordance with the Bohr’s model, find the quantum number that characterises the earth’s revolution around the sun in an orbit of radius 1.5 × 10¹¹ m with orbital speed 3 × 10⁴ m/s. (Mass of earth = 6.0 × 10²⁴ kg.)

Discussion

14.	a bullet of mass 10 g travelling horizontally with a velocity of 160 ms -1 strikes a stationary wooden block and comes to rest at 0.02 s. the distance of penetration of the bullet into the block will be
Answer» a bullet of mass 10 g travelling horizontally with a velocity of 160 ms -1 strikes a stationary wooden block and comes to rest at 0.02 s. the distance of penetration of the bullet into the block will be

Discussion

15.	57.Two point charges having equal charges separated 1m distance experience a force of 8N. What will be the force experience by them, if they are held in water, at the same distance? Given k water = 80
Answer» 57.Two point charges having equal charges separated 1m distance experience a force of 8N. What will be the force experience by them, if they are held in water, at the same distance? Given k water = 80

Discussion

16.	At a certain place a magnet makes 30 oscillations per minute in oscillation magnetometer at another place where horizontal component of Earth's magnetic field is four times the time period will be
Answer» At a certain place a magnet makes 30 oscillations per minute in oscillation magnetometer at another place where horizontal component of Earth's magnetic field is four times the time period will be

Discussion

17.	35. Calculate the rms speed of an ideal monatomic gas having molecular weight 28 gm/mol at 27 CIf the specific heats at constant pressure and volume are respectively 20.8 J mol-1 K-1 and12.5 J mol-1 K-1 respectively.
Answer» 35. Calculate the rms speed of an ideal monatomic gas having molecular weight 28 gm/mol at 27 CIf the specific heats at constant pressure and volume are respectively 20.8 J mol-1 K-1 and12.5 J mol-1 K-1 respectively.

Discussion

18.	In an alpha decay the atomic number of an element decreases by __.
Answer» In an alpha decay the atomic number of an element decreases by __.

Discussion

19.	Look at the activities listed below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.•Suma is swimming in a pond.•A donkey is carrying a load on its back.•A wind mill is lifting water from a well.•A green plant is carrying out photosynthesis.•An engine is pulling a train.•Food grains are getting dried in the sun.•A sailboat is moving due to wind energy.
Answer» Look at the activities listed below. Reason out whether or not work is done in the light of your understanding of the term ‘work’. •Suma is swimming in a pond. •A donkey is carrying a load on its back. •A wind mill is lifting water from a well. •A green plant is carrying out photosynthesis. •An engine is pulling a train. •Food grains are getting dried in the sun. •A sailboat is moving due to wind energy.

19.

Look at the activities listed below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.•Suma is swimming in a pond.•A donkey is carrying a load on its back.•A wind mill is lifting water from a well.•A green plant is carrying out photosynthesis.•An engine is pulling a train.•Food grains are getting dried in the sun.•A sailboat is moving due to wind energy.

Answer»

Look at the activities listed below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.

•Suma is swimming in a pond.

•A donkey is carrying a load on its back.

•A wind mill is lifting water from a well.

•A green plant is carrying out photosynthesis.

•An engine is pulling a train.

•Food grains are getting dried in the sun.

•A sailboat is moving due to wind energy.

Discussion

20.	A taxi leaves the station X for station Y every 10 minutes .simultaneously ,a taxi leaves the station Y also for station X every 10 minutes.The taxis move at the same constant speed and go from X to Y or vice -versa in 2hours .how many taxis coming from the other side will each taxi meet enroute from Y to X?
Answer» A taxi leaves the station X for station Y every 10 minutes .simultaneously ,a taxi leaves the station Y also for station X every 10 minutes.The taxis move at the same constant speed and go from X to Y or vice -versa in 2hours .how many taxis coming from the other side will each taxi meet enroute from Y to X?

Discussion

21.	A cylindrical metal rod of length L0 is shaped into a ring with a small gap as shown. On heating the system
Answer» A cylindrical metal rod of length $L_{0}$ is shaped into a ring with a small gap as shown. On heating the system

Discussion

22.	At an angle of 30∘ to the magnetic meridian, the apparent dip is 45∘. Find the true dip :
Answer» At an angle of $30^{\circ}$ to the magnetic meridian, the apparent dip is $45^{\circ}$ . Find the true dip :

Discussion

23.	The kinetic energy needed to project a body of mass m from the earth surface (radius R) to infinity is
Answer» The kinetic energy needed to project a body of mass $m$ from the earth surface $($ radius $R)$ to infinity is

Discussion

24.	{ A body of mass }40gm is moving with a constant }}{ velocity of }2cm/sec on a horizontal frictionless }} table. The force on table is
Answer» { A body of mass }40gm is moving with a constant }}{ velocity of }2cm/sec on a horizontal frictionless }} table. The force on table is

Discussion

25.	A +2 μC charge is at (-a, 0, 0) and a +2 µC charge is at (a, 0, O). Find the ratio of potential at points A (0, a, 0) and B (0, -a, 0)
Answer» A +2 μC charge is at (-a, 0, 0) and a +2 µC charge is at (a, 0, O). Find the ratio of potential at points A (0, a, 0) and B (0, -a, 0)

Discussion

26.	40. Calculate the quantity of electricity that would be required to reduce 12.3 g of nitrobenzene to aniline if the current efficiency for the process is 50% If the potential drop across the cell is 3 volts how much energy will be consumed
Answer» 40. Calculate the quantity of electricity that would be required to reduce 12.3 g of nitrobenzene to aniline if the current efficiency for the process is 50% If the potential drop across the cell is 3 volts how much energy will be consumed

Discussion

27.	An electrically heating coil was placed in a calorimeter containing 360 gm of water at 10∘C. The coil consumes energy at the rate of 90 watt. The water equivalent of the calorimeter and the coil is 40 gm. Calculate, what will be the temperature of the water after 10 minutes.(J = 4.2 Joule/cal.)
Answer» An electrically heating coil was placed in a calorimeter containing 360 gm of water at $10^{\circ} C$ . The coil consumes energy at the rate of 90 watt. The water equivalent of the calorimeter and the coil is 40 gm. Calculate, what will be the temperature of the water after 10 minutes. (J = 4.2 Joule/cal.)

Discussion

28.	The length of an elastic string is X m when the tension is 8 N, and Y m when the tension is 10 N. The length in metres when the tension is 18 N is
Answer» The length of an elastic string is X m when the tension is 8 N, and Y m when the tension is 10 N. The length in metres when the tension is 18 N is

Discussion

29.	In a potentiometerarrangement, a cell of emf 1.25 V gives a balance point at 35.0 cmlength of the wire. If the cell is replaced by another cell and thebalance point shifts to 63.0 cm, what is the emf of the second cell?
Answer» In a potentiometer arrangement, a cell of emf 1.25 V gives a balance point at 35.0 cm length of the wire. If the cell is replaced by another cell and the balance point shifts to 63.0 cm, what is the emf of the second cell?

Discussion

30.	State and explain the law of inertia.
Answer» State and explain the law of inertia.

Discussion

31.	Superman is going on a vacation to his home planet krypton from earth via. Sun. (Let's assume for a moment that Krypton is not destroyed). His energy v/s distance travelled graph is as shown below: Find the number of positions where dEds=0. Based on this find out the number of stars that Super man crossed on his way home from earth. (I hope you know that superman's source of energy is sunlight or star light so the more closer he goes to a star the more energy he has)
Answer» Superman is going on a vacation to his home planet krypton from earth via. Sun. (Let's assume for a moment that Krypton is not destroyed). His energy v/s distance travelled graph is as shown below: Find the number of positions where $\frac{d E}{d s}$ =0. Based on this find out the number of stars that Super man crossed on his way home from earth. (I hope you know that superman's source of energy is sunlight or star light so the more closer he goes to a star the more energy he has)

31.

Superman is going on a vacation to his home planet krypton from earth via. Sun. (Let's assume for a moment that Krypton is not destroyed). His energy v/s distance travelled graph is as shown below: Find the number of positions where dEds=0. Based on this find out the number of stars that Super man crossed on his way home from earth. (I hope you know that superman's source of energy is sunlight or star light so the more closer he goes to a star the more energy he has)

Answer»

Superman is going on a vacation to his home planet krypton from earth via. Sun. (Let's assume for a moment that Krypton is not destroyed). His energy v/s distance travelled graph is as shown below:

Find the number of positions where $\frac{d E}{d s}$ =0. Based on this find out the number of stars that Super man crossed on his way home from earth. (I hope you know that superman's source of energy is sunlight or star light so the more closer he goes to a star the more energy he has)

Discussion

32.	For a given velocity, a projectile has the same range R for two angles of projection if t1 and t2 are the times of flight in the two cases then
Answer» For a given velocity, a projectile has the same range R for two angles of projection if $t_{1}$ and $t_{2}$ are the times of flight in the two cases then

Discussion

33.	the slope of kinetic energy vs position graph gives us the time rate of change of
Answer» the slope of kinetic energy vs position graph gives us the time rate of change of

Discussion

34.	A man travelling in a car with a maximum constant speed of 20 m/s watches the friend start off at a distance 100 m/s ahead on a motor cycle with constant acceleration ‘a′. The maximum value of ‘a′ for which the man in the car can reach his friend is
Answer» A man travelling in a car with a maximum constant speed of $20 m/s$ watches the friend start off at a distance $100 m/s$ ahead on a motor cycle with constant acceleration $‘ a^{'}$ . The maximum value of $‘ a^{'}$ for which the man in the car can reach his friend is

Discussion

35.	The de Broglie wavelength of a neutron corresponding to root mean square speedat 927∘C is λ. What will be the de Broglie wavelength of the root mean square speed at 27∘C ?
Answer» The de Broglie wavelength of a neutron corresponding to root mean square speedat $927^{\circ} C is λ$ . What will be the de Broglie wavelength of the root mean square speed at $27^{\circ} C$ ?

Discussion

36.	A man swims across a river with speedbof 5 km/h (in still water) which a boat go' s to upstream with speed of 12km/h (in still water) how fas and in which direction does the man appear to go to the boatman ? Given that speed of flowing water is 2 km/h
Answer» A man swims across a river with speedbof 5 km/h (in still water) which a boat go' s to upstream with speed of 12km/h (in still water) how fas and in which direction does the man appear to go to the boatman ? Given that speed of flowing water is 2 km/h

Discussion

37.	2. What are the limitations of dimensional formula?
Answer» 2. What are the limitations of dimensional formula?

Discussion

38.	nt2 equal charges ,2.0x10 raise to power-7C each r held fixed at a sepration of 20cm and a third charge of equal magnitude is placed midway bw two charges .It is now moved to a point 20 cm from both the charges. how much work is done by the electric field during this process?n
Answer» nt2 equal charges ,2.0x10 raise to power-7C each r held fixed at a sepration of 20cm and a third charge of equal magnitude is placed midway bw two charges .It is now moved to a point 20 cm from both the charges. how much work is done by the electric field during this process?n

Discussion

39.	A block of mass m moving at a speed v compresses a spring through a distance x before its speed is reduced by a factor of 3. Find the spring constant of the spring.
Answer» A block of mass $m$ moving at a speed $v$ compresses a spring through a distance $x$ before its speed is reduced by a factor of $3$ . Find the spring constant of the spring.

Discussion

40.	A body is moving from rest under constant acceleration and let S1 be the displacement in the first (p−1) seconds and S2 be the displacement in the first p seconds. The displacement in (p2−p+1)th second will be
Answer» A body is moving from rest under constant acceleration and let $S_{1}$ be the displacement in the first $(p - 1)$ seconds and $S_{2}$ be the displacement in the first $p$ seconds. The displacement in $(p^{2} - p + 1)^{t h}$ second will be

Discussion

41.	Two resistances are connected in series as shown in the diagram.(i) What is the current through the 5 ohm resistance?(ii) What is the current through R?(iii) What is the value of R?(iv) What is the value of V? [5 MARKS]
Answer» Two resistances are connected in series as shown in the diagram. (i) What is the current through the 5 ohm resistance? (ii) What is the current through R? (iii) What is the value of R? (iv) What is the value of V? [5 MARKS]

Discussion

42.	A rod of length is 3 m and its mass acting per unit-lenght is directly proportional to distance x fronmone of its end then its centre of gravity from thatend will be at.(A) 1.5 m(B) 2 m(D) 3.0 m (C.B.S.E. 2002)(C) 2.5 mm
Answer» A rod of length is 3 m and its mass acting per unit-lenght is directly proportional to distance x fronmone of its end then its centre of gravity from thatend will be at.(A) 1.5 m(B) 2 m(D) 3.0 m (C.B.S.E. 2002)(C) 2.5 mm

Discussion

43.	A block of mass 5 kg tied at the end of a string is whirled round in a vertical circle of radius 1 m. The critical speed of the block at the top of its swing below which the string would slacken before the block reaches the top isTake (g = 10 m/s2)
Answer» A block of mass $5 kg$ tied at the end of a string is whirled round in a vertical circle of radius $1 m$ . The critical speed of the block at the top of its swing below which the string would slacken before the block reaches the top is Take $(g = 10 {m/s}^{2})$

Discussion

44.	14. A body is projected vertically upwards from the surface of a Planet of radius R with a velocity equal to half the escape velocity for that planet the maximum height attained by the body is
Answer» 14. A body is projected vertically upwards from the surface of a Planet of radius R with a velocity equal to half the escape velocity for that planet the maximum height attained by the body is

Discussion

45.	At 50 Hz operation, a single phase transformer has hysteresis loss of 200 W and eddy current loss of 100 W. Its core loss at 60 Hz operation at constant flux density will be_______W.384
Answer» At 50 Hz operation, a single phase transformer has hysteresis loss of 200 W and eddy current loss of 100 W. Its core loss at 60 Hz operation at constant flux density will be_______W. 384

Discussion

46.	Two vectors have magnitudes 3 units and 6 units respectively. What should be the angle between these two vectors if the resultant vector is perpendicular to the smaller one?
Answer» Two vectors have magnitudes $3$ units and $6$ units respectively. What should be the angle between these two vectors if the resultant vector is perpendicular to the smaller one?

Discussion

47.	In pure inductive circuit, the curvesbetween frequency f and reciprocal ofinductive reactance 1/XLis
Answer» In pure inductive circuit, the curves between frequency f and reciprocal of inductive reactance 1/X_L is

Discussion

48.	If y=x3+2x2+7x+8, then dydx will be
Answer» If $y = x^{3} + 2 x^{2} + 7 x + 8$ , then $\frac{d y}{d x}$ will be

Discussion

49.	Electronic and proton move with same speed in same fir which one has greater radius of circular path in magnetic field
Answer» Electronic and proton move with same speed in same fir which one has greater radius of circular path in magnetic field

Discussion

50.	Two bodies of masses m and 4m are placed at a distance r from each other. The gravitational potential at a point on the line joining them where the gravitational field is zero is
Answer» Two bodies of masses $m$ and $4 m$ are placed at a distance $r$ from each other. The gravitational potential at a point on the line joining them where the gravitational field is zero is

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

A cylindrical tube open at both the ends has a fundamentaf requency of 390 Hz in air. If 1/4 -th of the tube is immersed vertically in water the fundamental frequency of air column is

Why is gravitational field intensity zero inside the spherical shell although constant in case of gravitational potential ?

46.The phase difference between current and voltage, when the freqeuency of applied emf is w + R/2L (w is resonance frequency) in a series LCR circuit is (a) pi/2 (b) pi/4 (c)pi/6 (d)0

Force F=2i-3j+2k acting on a particle about the point O such that it's position vector r=i+k , then find the angle between the force and position vector and also find out the torque.

Nuclei of radioactive element A are produced at rate t2 at any time t. The element A has decay constant λ. Let N be the number of nuclei of element A at any time t. At time t=t0, dNdt is minimum. Then the number of nuclei of element A at time t=t0 is :

A uniform wire is stretched uniformed by 0.5%.Its resistance change by

In a projectile motion, velocity at maximum height is

Two bulbs, one of 200 Volts,60 Watts and the other of 200 Volts,100 Watts are connected in series to a 200 Volt supply. The power consumed will be

if the length of the conductor is strected by 20 % , percentage of net resistance is ?

The graph represents the s-t curve of a body moving in a straight line. At which moment 't' is the instantaneous velocity approximately equal to the average velocity over the first 't' seconds?

A rabbit runs across a parking lot on which a set of coordinate axes has, strangely enough, been drawn. The coordinates (meters) of the rabbit's position as function of time t(seconds) are given by x(t)=−t22+5t+20 And y(t)=t2−10t+30 Find the velocity at time t = 15s.

In accordance with theBohr’s model, find the quantum number that characterises theearth’s revolution around the sun in an orbit of radius 1.5 ×1011 m with orbital speed 3 × 104 m/s.(Mass of earth = 6.0 × 1024 kg.)

a bullet of mass 10 g travelling horizontally with a velocity of 160 ms -1 strikes a stationary wooden block and comes to rest at 0.02 s. the distance of penetration of the bullet into the block will be

57.Two point charges having equal charges separated 1m distance experience a force of 8N. What will be the force experience by them, if they are held in water, at the same distance? Given k water = 80

At a certain place a magnet makes 30 oscillations per minute in oscillation magnetometer at another place where horizontal component of Earth's magnetic field is four times the time period will be

35. Calculate the rms speed of an ideal monatomic gas having molecular weight 28 gm/mol at 27 CIf the specific heats at constant pressure and volume are respectively 20.8 J mol-1 K-1 and12.5 J mol-1 K-1 respectively.

In an alpha decay the atomic number of an element decreases by __.

A cylindrical metal rod of length L0 is shaped into a ring with a small gap as shown. On heating the system

At an angle of 30∘ to the magnetic meridian, the apparent dip is 45∘. Find the true dip :

The kinetic energy needed to project a body of mass m from the earth surface (radius R) to infinity is

{ A body of mass }40gm is moving with a constant }}{ velocity of }2cm/sec on a horizontal frictionless }} table. The force on table is

A +2 μC charge is at (-a, 0, 0) and a +2 µC charge is at (a, 0, O). Find the ratio of potential at points A (0, a, 0) and B (0, -a, 0)

40. Calculate the quantity of electricity that would be required to reduce 12.3 g of nitrobenzene to aniline if the current efficiency for the process is 50% If the potential drop across the cell is 3 volts how much energy will be consumed

An electrically heating coil was placed in a calorimeter containing 360 gm of water at 10∘C. The coil consumes energy at the rate of 90 watt. The water equivalent of the calorimeter and the coil is 40 gm. Calculate, what will be the temperature of the water after 10 minutes.(J = 4.2 Joule/cal.)

The length of an elastic string is X m when the tension is 8 N, and Y m when the tension is 10 N. The length in metres when the tension is 18 N is

In a potentiometerarrangement, a cell of emf 1.25 V gives a balance point at 35.0 cmlength of the wire. If the cell is replaced by another cell and thebalance point shifts to 63.0 cm, what is the emf of the second cell?

State and explain the law of inertia.

For a given velocity, a projectile has the same range R for two angles of projection if t1 and t2 are the times of flight in the two cases then

the slope of kinetic energy vs position graph gives us the time rate of change of

A man travelling in a car with a maximum constant speed of 20 m/s watches the friend start off at a distance 100 m/s ahead on a motor cycle with constant acceleration ‘a′. The maximum value of ‘a′ for which the man in the car can reach his friend is

The de Broglie wavelength of a neutron corresponding to root mean square speedat 927∘C is λ. What will be the de Broglie wavelength of the root mean square speed at 27∘C ?

A man swims across a river with speedbof 5 km/h (in still water) which a boat go' s to upstream with speed of 12km/h (in still water) how fas and in which direction does the man appear to go to the boatman ? Given that speed of flowing water is 2 km/h

2. What are the limitations of dimensional formula?

nt2 equal charges ,2.0x10 raise to power-7C each r held fixed at a sepration of 20cm and a third charge of equal magnitude is placed midway bw two charges .It is now moved to a point 20 cm from both the charges. how much work is done by the electric field during this process?n

A block of mass m moving at a speed v compresses a spring through a distance x before its speed is reduced by a factor of 3. Find the spring constant of the spring.

A body is moving from rest under constant acceleration and let S1 be the displacement in the first (p−1) seconds and S2 be the displacement in the first p seconds. The displacement in (p2−p+1)th second will be

Two resistances are connected in series as shown in the diagram.(i) What is the current through the 5 ohm resistance?(ii) What is the current through R?(iii) What is the value of R?(iv) What is the value of V? [5 MARKS]

A rod of length is 3 m and its mass acting per unit-lenght is directly proportional to distance x fronmone of its end then its centre of gravity from thatend will be at.(A) 1.5 m(B) 2 m(D) 3.0 m (C.B.S.E. 2002)(C) 2.5 mm

A block of mass 5 kg tied at the end of a string is whirled round in a vertical circle of radius 1 m. The critical speed of the block at the top of its swing below which the string would slacken before the block reaches the top isTake (g = 10 m/s2)

14. A body is projected vertically upwards from the surface of a Planet of radius R with a velocity equal to half the escape velocity for that planet the maximum height attained by the body is

At 50 Hz operation, a single phase transformer has hysteresis loss of 200 W and eddy current loss of 100 W. Its core loss at 60 Hz operation at constant flux density will be_______W.384

Two vectors have magnitudes 3 units and 6 units respectively. What should be the angle between these two vectors if the resultant vector is perpendicular to the smaller one?

In pure inductive circuit, the curvesbetween frequency f and reciprocal ofinductive reactance 1/XLis

If y=x3+2x2+7x+8, then dydx will be

Electronic and proton move with same speed in same fir which one has greater radius of circular path in magnetic field

Two bodies of masses m and 4m are placed at a distance r from each other. The gravitational potential at a point on the line joining them where the gravitational field is zero is