50278 + Interview Questions in Physics

1.	Liquid reaches an equilibrium as shown in a capillary tube of internal radius r=1 cm. If the surface tension of the liquid is T=0.07 N/m. The angle of contact θ=60∘ and density of liquid ρ=103 kg/m3, then the pressure difference between P and Q is Take atmospheric pressure as 105 N/m2.
Answer» Liquid reaches an equilibrium as shown in a capillary tube of internal radius $r = 1 cm$ . If the surface tension of the liquid is $T = 0.07 N/m$ . The angle of contact $θ = 60^{\circ}$ and density of liquid $ρ = 10^{3} {kg/m}^{3}$ , then the pressure difference between $P$ and $Q$ is Take atmospheric pressure as $10^{5} {N/m}^{2}$ .

Discussion

2.	A 4.0 kg block is suspended from the ceiling of an elevator through a string having a linear mass density of 19.2×10 kg m−1. Find the speed (with respect to the string) with which a wave pulse can proceed on the string if the elevator accelerates up at the rate of 2.0 ms−2. Take g=10 ms−2.
Answer» A 4.0 kg block is suspended from the ceiling of an elevator through a string having a linear mass density of $19.2 \times 10 k g m^{- 1}$ . Find the speed (with respect to the string) with which a wave pulse can proceed on the string if the elevator accelerates up at the rate of $2.0 m s^{- 2}$ . Take $g = 10 m s^{- 2} .$

Discussion

3.	The horizontal range and the maximum height of a projectile are equal. The angle of projection of the projectile is
Answer» The horizontal range and the maximum height of a projectile are equal. The angle of projection of the projectile is

Discussion

4.	The focus in terms of a parabolic mirror is where:
Answer» The focus in terms of a parabolic mirror is where:

Discussion

5.	A muonic atom contains a nucleus of charge Ze and a negative muon, μ−, moving about it. The μ− is an elementary charge with -e and a mass that is approximately 200 times as large as an electron mass. The first Bohr orbit of the muonic atom with Z=1 is found out to be k×10−13 m. Then the value of k is
Answer» A muonic atom contains a nucleus of charge Ze and a negative muon, $μ^{-}$ , moving about it. The $μ^{-}$ is an elementary charge with -e and a mass that is approximately 200 times as large as an electron mass. The first Bohr orbit of the muonic atom with $Z = 1$ is found out to be $k \times 10^{- 13} m$ . Then the value of $k$ is

Discussion

6.	Write two properties of a material suitable for making (a) a permanent magnet, and (b) an electromagnet.
Answer» Write two properties of a material suitable for making (a) a permanent magnet, and (b) an electromagnet.

Discussion

7.	A 300 g mass has a velocity of (3^i+4^j)m/s at a certain instant. What is its kinetic energy?
Answer» A 300 g mass has a velocity of $(3^i + 4^j) m / s$ at a certain instant. What is its kinetic energy?

Discussion

8.	Particle 'A' moves with speed 10 m/s in a frictionless circular fixed horiozontal pipe of radius 5 m and strikes with ′B′ of double mass that of A. Coefficient of resitution is 12 and particle 'A' starts its journey at t=0. The time at which second collision occurs is:
Answer» Particle 'A' moves with speed $10 m/s$ in a frictionless circular fixed horiozontal pipe of radius $5$ m and strikes with $^{'} B^{'}$ of double mass that of A. Coefficient of resitution is $\frac{1}{2}$ and particle 'A' starts its journey at $t = 0$ . The time at which second collision occurs is:

Discussion

9.	The air density at Mount Everest is less than that at the sea level. Mountaineers find that for one trip lasting a few hours, the extra oxygen needed by them corresponds to 30,000 cc at sea level (pressure 1 atmosphere, temperature 27∘C). Assuming that the temperature around Mount Everest is –73∘C and that the oxygen cylinder has a capacity of 5.2 litre, the pressure at which O2 be filled (at site) in the cylinder is
Answer» The air density at Mount Everest is less than that at the sea level. Mountaineers find that for one trip lasting a few hours, the extra oxygen needed by them corresponds to $30, 000 cc$ at sea level (pressure 1 atmosphere, temperature $27^{\circ} C$ ). Assuming that the temperature around Mount Everest is $- 73^{\circ} C$ and that the oxygen cylinder has a capacity of $5.2 litre$ , the pressure at which $O_{2}$ be filled (at site) in the cylinder is

Discussion

10.	A proton describes a circle of radius 1 cm in a magnetic field of strength 0.10 T. What would be the radius of the circle described by an α−particle moving with the same speed in the same magnetic field ?
Answer» A proton describes a circle of radius 1 cm in a magnetic field of strength 0.10 T. What would be the radius of the circle described by an $α -$ particle moving with the same speed in the same magnetic field ?

Discussion

11.	origin) on the ground with a speed of 50 m/s at an angle of 53∘ with the horizontal. It just passes two points A and B each at height 75 m above horizontal as shown. The horizontal separation between the points A and B is (Take g=10 m/s2)
Answer» origin) on the ground with a speed of $50 m /$ s at an angle of $53^{\circ}$ with the horizontal. It just passes two points $A$ and $B$ each at height $75 m$ above horizontal as shown. The horizontal separation between the points $A$ and $B$ is (Take $g = 10 m / s^{2}$ )

Discussion

12.	What is the equivalent spring constant for the system shown below?
Answer» What is the equivalent spring constant for the system shown below?

Discussion

13.	In the figure shown, if the block does not slide down the plane when a force of 10 N is applied perpendicular to the plane, find the coefficient of static friction between the plane and the block.(Consider limiting case of friction) Take g=10 m/s2.
Answer» In the figure shown, if the block does not slide down the plane when a force of $10 N$ is applied perpendicular to the plane, find the coefficient of static friction between the plane and the block.(Consider limiting case of friction) Take $g = {10 m/s}^{2} .$

Discussion

14.	3.80 gm of metal M is deposited at the cathode by passing 0.2 F of electricity through the solution of metal chlorides. The formula of the metal chloride is: (atomic mass of M = 57 g/mol)
Answer» 3.80 gm of metal M is deposited at the cathode by passing 0.2 F of electricity through the solution of metal chlorides. The formula of the metal chloride is: (atomic mass of M = 57 g/mol)

Discussion

15.	Figure shows a vessel partitioned by a fixed diathermic separator. Different ideal gases are filled in the two parts. The rms speed of the molecules in the left part equals the mean speed of the molecules in the right part. Calculate the ratio of the mass of a molecule in the left part to the mass of a molecule in the right part.
Answer» Figure shows a vessel partitioned by a fixed diathermic separator. Different ideal gases are filled in the two parts. The rms speed of the molecules in the left part equals the mean speed of the molecules in the right part. Calculate the ratio of the mass of a molecule in the left part to the mass of a molecule in the right part.

15.

Figure shows a vessel partitioned by a fixed diathermic separator. Different ideal gases are filled in the two parts. The rms speed of the molecules in the left part equals the mean speed of the molecules in the right part. Calculate the ratio of the mass of a molecule in the left part to the mass of a molecule in the right part.

Answer»

Figure shows a vessel partitioned by a fixed diathermic separator. Different ideal gases are filled in the two parts. The rms speed of the molecules in the left part equals the mean speed of the molecules in the right part. Calculate the ratio of the mass of a molecule in the left part to the mass of a molecule in the right part.

Discussion

16.	The first order diffraction of X-rays from a certain set of crystal planes occur at an angle of 11.8∘ from the planes. If the planes are 281 pm apart, what is the wavelength of X-rays (sin 11.8∘ = 0.2045)
Answer» The first order diffraction of X-rays from a certain set of crystal planes occur at an angle of ${11.8}^{\circ}$ from the planes. If the planes are 281 pm apart, what is the wavelength of X-rays (sin ${11.8}^{\circ}$ = 0.2045)

Discussion

17.	Suppose the platform with the kid in the previous problem is rotating in anticlockwise direction at an angular speed ω. The kid starts walking along the rim with a speed v relative to the platform also in the anticlockwise direction. Find the new angular speed of the platform.
Answer» Suppose the platform with the kid in the previous problem is rotating in anticlockwise direction at an angular speed $ω$ . The kid starts walking along the rim with a speed v relative to the platform also in the anticlockwise direction. Find the new angular speed of the platform.

Discussion

18.	A man of height h walks in a straight path towards a lamp post of height H with velocity v. Then velocity of the edge of the shadow on the ground will be
Answer» A man of height $h$ walks in a straight path towards a lamp post of height $H$ with velocity $v$ . Then velocity of the edge of the shadow on the ground will be

Discussion

19.	A charged particle is projected with velocity →v=u^i from the origin, in a region having electric field →E and magnetic field →B both. Value of →B and →E are given in column 1 and column 2 respectively and path of the particle is given in column 3. Column 1 Column 2 Column 3 (Magnetic field) (Electric field) (Path of particle)(i)→B=0(i)→E=0(P)Circular path(ii)→B=B0^i+B0^j(ii)→E=E0^i(Q)Helical path(iii)→B=B0^j+B0^k(iii)→E=B0u(^j−^k)(R)Cycloid(iv)→B=B0^k(iv)→E=E0^k(S)Straight line In which of the following combination particle moves in uniform circular motion?
Answer» A charged particle is projected with velocity $\to v = u^i$ from the origin, in a region having electric field $\to E$ and magnetic field $\to B$ both. Value of $\to B$ and $\to E$ are given in column 1 and column 2 respectively and path of the particle is given in column 3. $\begin{matrix} Column 1 & Column 2 & Column 3 (Magnetic field) & (Electric field) & (Path of particle) (i) & \to B = 0 & (i) & \to E = 0 & (P) & Circular path (i i) & \to B = B_{0}^i + B_{0}^j & (i i) & \to E = E_{0}^i & (Q) & Helical path (i i i) & \to B = B_{0}^j + B_{0}^k & (i i i) & \to E = B_{0} u (^j -^k) & (R) & Cycloid (i v) & \to B = B_{0}^k & (i v) & \to E = E_{0}^k & (S) & Straight line \end{matrix}$ In which of the following combination particle moves in uniform circular motion?

19.

A charged particle is projected with velocity →v=u^i from the origin, in a region having electric field →E and magnetic field →B both. Value of →B and →E are given in column 1 and column 2 respectively and path of the particle is given in column 3. Column 1 Column 2 Column 3 (Magnetic field) (Electric field) (Path of particle)(i)→B=0(i)→E=0(P)Circular path(ii)→B=B0^i+B0^j(ii)→E=E0^i(Q)Helical path(iii)→B=B0^j+B0^k(iii)→E=B0u(^j−^k)(R)Cycloid(iv)→B=B0^k(iv)→E=E0^k(S)Straight line In which of the following combination particle moves in uniform circular motion?

Answer»

A charged particle is projected with velocity $\to v = u^i$ from the origin, in a region having electric field $\to E$ and magnetic field $\to B$ both. Value of $\to B$ and $\to E$ are given in column 1 and column 2 respectively and path of the particle is given in column 3.

$\begin{matrix} Column 1 & Column 2 & Column 3 (Magnetic field) & (Electric field) & (Path of particle) (i) & \to B = 0 & (i) & \to E = 0 & (P) & Circular path (i i) & \to B = B_{0}^i + B_{0}^j & (i i) & \to E = E_{0}^i & (Q) & Helical path (i i i) & \to B = B_{0}^j + B_{0}^k & (i i i) & \to E = B_{0} u (^j -^k) & (R) & Cycloid (i v) & \to B = B_{0}^k & (i v) & \to E = E_{0}^k & (S) & Straight line \end{matrix}$

In which of the following combination particle moves in uniform circular motion?

Discussion

20.	A spring of stiffness K is kept compressed by applying horizontal force on a block of mass m by a length x0=(mgk) as shown in the figure. If the force F is withdrawn suddenly, the block oscillates and finally stops. In consequence, fractional loss of energy is equal to 50% of the initial potential energy stored in the spring. The coefficient of friction between block and ground is found as [x]−12 ; what is x? ___
Answer» A spring of stiffness K is kept compressed by applying horizontal force on a block of mass m by a length $x_{0} = (\frac{m g}{k})$ as shown in the figure. If the force F is withdrawn suddenly, the block oscillates and finally stops. In consequence, fractional loss of energy is equal to $50 %$ of the initial potential energy stored in the spring. The coefficient of friction between block and ground is found as $[x]^{\frac{- 1}{2}}$ ; what is x? ___

Discussion

21.	In the circuit shown in figure switch S is closed at time t = 0. Let i1 and i2 be the currents at any finite time t then the ratio
Answer» In the circuit shown in figure switch S is closed at time t = 0. Let i₁ and i₂ be the currents at any finite time t then the ratio

21.

In the circuit shown in figure switch S is closed at time t = 0. Let i1 and i2 be the currents at any finite time t then the ratio

Answer»

In the circuit shown in figure switch S is closed at time t = 0. Let i₁ and i₂ be the currents at any finite time t then

the ratio

Discussion

22.	A seconds metallic pendulum keeps correct time at 0∘ C. If it loses 12.5 s a day at 25∘ C, the coefficient of linear expansion of metal pendulum is
Answer» A seconds metallic pendulum keeps correct time at $0^{\circ} C$ . If it loses $12.5 s$ a day at $25^{\circ} C$ , the coefficient of linear expansion of metal pendulum is

Discussion

23.	In the given figure , a=10√2 m/s2 represents the total acceleration of a particle moving in the clockwise direction in a circle of radius R=2 m at a given instant of time. Speed of the particle is
Answer» In the given figure , $a = 10 \sqrt{2} {m/s}^{2}$ represents the total acceleration of a particle moving in the clockwise direction in a circle of radius $R = 2 m$ at a given instant of time. Speed of the particle is

Discussion

24.

In a photoelectric experiment, the potential difference V that must be maintained between the illuminated surface and the collector so as just to prevent any electron from reaching the collector is determined for different frequencies f of the incident illumination. The graph obtained is shown. The maximim kinetic energy of the electrons emitted at frequency f1 is

Answer»

In a photoelectric experiment, the potential difference

V

that must be maintained between the illuminated surface and the collector so as just to prevent any electron from reaching the collector is determined for different frequencies

f

of the incident illumination.
The graph obtained is shown. The maximim kinetic energy of the electrons emitted at frequency

f_{1}

is

Discussion

25.	A convex lens of focal length 50 cm is cut along the diameter into two identity halves A and B and in the process a layer C of the lens thickness 1 mm is lost. Then the two halves A and B are put together to form a composite lens. Now in front of this composite lens a source of light emitting wavelength λ=6000 ∘A is placed at a distance of 25 cm as shown in the figure. Behind the lens there is a screen at a distance 50 cm from it. Choose the correct option(s):
Answer» A convex lens of focal length 50 cm is cut along the diameter into two identity halves A and B and in the process a layer C of the lens thickness 1 mm is lost. Then the two halves A and B are put together to form a composite lens. Now in front of this composite lens a source of light emitting wavelength $λ = 6000 \circ A$ is placed at a distance of 25 cm as shown in the figure. Behind the lens there is a screen at a distance 50 cm from it. Choose the correct option(s):

25.

A convex lens of focal length 50 cm is cut along the diameter into two identity halves A and B and in the process a layer C of the lens thickness 1 mm is lost. Then the two halves A and B are put together to form a composite lens. Now in front of this composite lens a source of light emitting wavelength λ=6000 ∘A is placed at a distance of 25 cm as shown in the figure. Behind the lens there is a screen at a distance 50 cm from it. Choose the correct option(s):

Answer»

A convex lens of focal length 50 cm is cut along the diameter into two identity halves A and B and in the process a layer C of the lens thickness 1 mm is lost. Then the two halves A and B are put together to form a composite lens. Now in front of this composite lens a source of light emitting wavelength $λ = 6000 \circ A$ is placed at a distance of 25 cm as shown in the figure. Behind the lens there is a screen at a distance 50 cm from it. Choose the correct option(s):

Discussion

26.	In a resonance tube experiment when a tuning fork of frequency 500 Hz is sounded over it, the first and second resonances are obtained at 17 cm and 52cm. the velocity of sound is Ans is 350 m/s. Please give detailed explanation as I won't be able to understand concise answers.
Answer» In a resonance tube experiment when a tuning fork of frequency 500 Hz is sounded over it, the first and second resonances are obtained at 17 cm and 52cm. the velocity of sound is Ans is 350 m/s. Please give detailed explanation as I won't be able to understand concise answers.

26.

In a resonance tube experiment when a tuning fork of frequency 500 Hz is sounded over it, the first and second resonances are obtained at 17 cm and 52cm. the velocity of sound is Ans is 350 m/s. Please give detailed explanation as I won't be able to understand concise answers.

Answer»

In a resonance tube experiment when a tuning fork of frequency 500 Hz is sounded over it, the first and second resonances are obtained at 17 cm and 52cm. the velocity of sound is

Ans is 350 m/s.

Please give detailed explanation as I won't be able to understand concise answers.

Discussion

27.	What is the effect of temperature on elasticity ? State reason .
Answer» What is the effect of temperature on elasticity ? State reason .

Discussion

28.	A particle in a certain consevative force field has a potential energy given by U=20xyz. The force exerted on it is
Answer» A particle in a certain consevative force field has a potential energy given by $U = \frac{20 x y}{z}$ . The force exerted on it is

Discussion

29.	Find the power of a pump which takes 10 s to draw 100 kg of water from a tank situated at a height of 20 m. (correct answer + 1, wrong answer - 0.25)
Answer» Find the power of a pump which takes $10 s$ to draw $100 kg$ of water from a tank situated at a height of $20 m$ . (correct answer + 1, wrong answer - 0.25)

Discussion

30.	A longitudinal wave is represented by x=x0 sin 2π(nt−xλ). The maximum particle velocity will be four times the wave velocity if:
Answer» A longitudinal wave is represented by $x = x_{0} s i n 2 π (n t - \frac{x}{λ})$ . The maximum particle velocity will be four times the wave velocity if:

Discussion

31.	Write a schematic diagram of a single slit diffraction experiment and write condition for minima and secondary maxima.
Answer» Write a schematic diagram of a single slit diffraction experiment and write condition for minima and secondary maxima.

Discussion

32.	A rod PQ of length ℓ is rotating with angular velocity ω about its mid-point, in a uniform magnetic field B which is perpendicular to the plane of rotation of the rod. Find the induced emf between PQ. ?
Answer» A rod PQ of length $ℓ$ is rotating with angular velocity $ω$ about its mid-point, in a uniform magnetic field B which is perpendicular to the plane of rotation of the rod. Find the induced emf between PQ. ?

Discussion

33.	When the kinetic energy of a body executing SHM is 1/3 of the potential energy. The displacement of the body is x percent of the amplitude, where x is a.) 33 b.) 87 c.) 67 d.) 50
Answer» When the kinetic energy of a body executing SHM is 1/3 of the potential energy. The displacement of the body is x percent of the amplitude, where x is a.) 33 b.) 87 c.) 67 d.) 50

33.

When the kinetic energy of a body executing SHM is 1/3 of the potential energy. The displacement of the body is x percent of the amplitude, where x is a.) 33 b.) 87 c.) 67 d.) 50

Answer»

When the kinetic energy of a body executing SHM is 1/3 of the potential energy. The displacement of the body is x percent of the amplitude, where x is

a.) 33

b.) 87

c.) 67

d.) 50

Discussion

34.	An ideal gas is kept inside a 4 L container at a temperature of 300 k and a pressure of 6 atmospheres. If the pressure is held constant while the volume of the gas is doubled, then find out the new temperature of the gas.
Answer» An ideal gas is kept inside a $4 L$ container at a temperature of $300 k$ and a pressure of $6 atmospheres$ . If the pressure is held constant while the volume of the gas is doubled, then find out the new temperature of the gas.

Discussion

35.	What is the significance of rms velocity of gas molecules?
Answer» What is the significance of rms velocity of gas molecules?

Discussion

36.	In the circuit shown in figure, cells of emf 2,1,3 and 1 V, respectively and resistances 2 Ω,1 Ω,3 Ω and 1 Ω are their internal resistances respectively. The potential difference between D and B is given as n13 volts. Find n.
Answer» In the circuit shown in figure, cells of emf 2,1,3 and $1 V$ , respectively and resistances $2 Ω, 1 Ω, 3 Ω$ and $1 Ω$ are their internal resistances respectively. The potential difference between $D$ and $B$ is given as $\frac{n}{13}$ volts. Find $n$ .

Discussion

37.	An electro-magnetic wave in vacuum has the electric and magnetic fields as ¯E and ¯B , which are always perpendicular to each other. The direction of polarization is given by ¯X and that of the wave propagation as ¯k. Then
Answer» An electro-magnetic wave in vacuum has the electric and magnetic fields as $¯ E a n d ¯ B$ , which are always perpendicular to each other. The direction of polarization is given by $¯ X$ and that of the wave propagation as $¯ k$ . Then

Discussion

38.	In the given figure a =15 m/s2 represents the total acceleration of a particle moving in clockwise direction in a circle of radius R = 2.5m at a given instant of time. The speed of the particle is:
Answer» In the given figure a $= 15 m / s^{2}$ represents the total acceleration of a particle moving in clockwise direction in a circle of radius R = 2.5m at a given instant of time. The speed of the particle is:

38.

In the given figure a =15 m/s2 represents the total acceleration of a particle moving in clockwise direction in a circle of radius R = 2.5m at a given instant of time. The speed of the particle is:

Answer»

In the given figure a $= 15 m / s^{2}$ represents the total acceleration of a particle moving in clockwise direction in a circle of radius R = 2.5m at a given instant of time. The speed of the particle is:

Discussion

39.	A car is moving in a rainstorm at a speed of 60 km/h. The rain drops fall vertically w.r.t the ground with a constant speed of 15 m/s. The angle with the vertical at which raindrops strike the car is
Answer» A car is moving in a rainstorm at a speed of $60 km/h$ . The rain drops fall vertically w.r.t the ground with a constant speed of $15 m/s$ . The angle with the vertical at which raindrops strike the car is

Discussion

40.	An inductor (L=0.03 H) and a resistor (R=0.15 kΩ) are connected in series to a battery of 15 V emf in a circuit shown below. The key K1 has been kept closed for a long time. Then at t=0,K1 is opened and key K2 is closed simultaneously. At t=1 ms, the current in the circuit will be (e5≅150)
Answer» An inductor ( $L = 0.03 H$ ) and a resistor ( $R = 0.15 k Ω$ ) are connected in series to a battery of $15 V$ emf in a circuit shown below. The key $K_{1}$ has been kept closed for a long time. Then at $t = 0, K_{1}$ is opened and key $K_{2}$ is closed simultaneously. At $t = 1 m s$ , the current in the circuit will be $(e^{5} ≅ 150)$

Discussion

41.	In sound waves,a displacement node is a pressure antinode snd vice versa.Explain why?
Answer» In sound waves,a displacement node is a pressure antinode snd vice versa.Explain why?

Discussion

42.	Length l and Acceleration due to gravity g are measured with ± 6 % and ± 4 % errors respectively. The percentage error in determination of the Time period of a simple pendulum will be,
Answer» Length $l$ and Acceleration due to gravity $g$ are measured with $\pm 6 %$ and $\pm 4 %$ errors respectively. The percentage error in determination of the Time period of a simple pendulum will be,

Discussion

43.	The figure shows a block of mass m placed on a smooth wedge of mass M. The value of M' is just sufficient, so that the block of mass m moves vertically downwards with acceleration 10 m/s2. Chose the correct option:
Answer» The figure shows a block of mass m placed on a smooth wedge of mass M. The value of M' is just sufficient, so that the block of mass m moves vertically downwards with acceleration 10 m/ $s^{2}$ _.Chose the correct option:

43.

The figure shows a block of mass m placed on a smooth wedge of mass M. The value of M' is just sufficient, so that the block of mass m moves vertically downwards with acceleration 10 m/s2. Chose the correct option:

Answer»

The figure shows a block of mass m placed on a smooth wedge of mass M. The value of M' is just sufficient, so that the block of mass m moves vertically downwards with acceleration 10 m/ $s^{2}$ _.Chose the correct option:

Discussion

44.	Find the velocity at the highest point, if it's projected with a speed 15ms^-1, in the direction 45° above the horizontal. Take g = 10 ms^-2
Answer» Find the velocity at the highest point, if it's projected with a speed 15ms^-1, in the direction 45° above the horizontal. Take g = 10 ms^-2

Discussion

45.	an elastic spring of unstretched lenght L and force constant K is stretched by a small length C it is further stretched by a small length Y the qork done in seconh stretching is
Answer» an elastic spring of unstretched lenght L and force constant K is stretched by a small length C it is further stretched by a small length Y the qork done in seconh stretching is

Discussion

46.	How long after the beginning of motion is the displacement of a harmonically oscillating point equal to one half its amplitude,if the period is 24 sec and initial phase is zero?
Answer» How long after the beginning of motion is the displacement of a harmonically oscillating point equal to one half its amplitude,if the period is 24 sec and initial phase is zero?

Discussion

47.	Two pith balls, each carrying charge +q are hung from a hook by two strings. It is found that when each charge is tripled, angle between the strings double. What was the initial angle between the strings?
Answer» Two pith balls, each carrying charge +q are hung from a hook by two strings. It is found that when each charge is tripled, angle between the strings double. What was the initial angle between the strings?

Discussion

48.	A body of mass 8m is kept in X−Y plane at rest. If it suddenly explodes into three pieces with two of them moving perpendicular to each other at equal speeds, the kinetic energy generated during explosion is (refer figure)
Answer» A body of mass $8 m$ is kept in $X - Y$ plane at rest. If it suddenly explodes into three pieces with two of them moving perpendicular to each other at equal speeds, the kinetic energy generated during explosion is (refer figure)

Discussion

49.	A simple pendulum is carried at a depth of 1 km below sea level. It becomes
Answer» A simple pendulum is carried at a depth of 1 km below sea level. It becomes

Discussion

50.	A rope of mass m0 and length L is suspended vertically. If a mass m is suspended from the bottom of the rope, find the time for a transverse wave to travel the length of the rope.
Answer» A rope of mass $m_{0}$ and length L is suspended vertically. If a mass m is suspended from the bottom of the rope, find the time for a transverse wave to travel the length of the rope.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Liquid reaches an equilibrium as shown in a capillary tube of internal radius r=1 cm. If the surface tension of the liquid is T=0.07 N/m. The angle of contact θ=60∘ and density of liquid ρ=103 kg/m3, then the pressure difference between P and Q is Take atmospheric pressure as 105 N/m2.

A 4.0 kg block is suspended from the ceiling of an elevator through a string having a linear mass density of 19.2×10 kg m−1. Find the speed (with respect to the string) with which a wave pulse can proceed on the string if the elevator accelerates up at the rate of 2.0 ms−2. Take g=10 ms−2.

The horizontal range and the maximum height of a projectile are equal. The angle of projection of the projectile is

The focus in terms of a parabolic mirror is where:

Write two properties of a material suitable for making (a) a permanent magnet, and (b) an electromagnet.

A 300 g mass has a velocity of (3^i+4^j)m/s at a certain instant. What is its kinetic energy?

Particle 'A' moves with speed 10 m/s in a frictionless circular fixed horiozontal pipe of radius 5 m and strikes with ′B′ of double mass that of A. Coefficient of resitution is 12 and particle 'A' starts its journey at t=0. The time at which second collision occurs is:

A proton describes a circle of radius 1 cm in a magnetic field of strength 0.10 T. What would be the radius of the circle described by an α−particle moving with the same speed in the same magnetic field ?

origin) on the ground with a speed of 50 m/s at an angle of 53∘ with the horizontal. It just passes two points A and B each at height 75 m above horizontal as shown. The horizontal separation between the points A and B is (Take g=10 m/s2)

What is the equivalent spring constant for the system shown below?

In the figure shown, if the block does not slide down the plane when a force of 10 N is applied perpendicular to the plane, find the coefficient of static friction between the plane and the block.(Consider limiting case of friction) Take g=10 m/s2.

3.80 gm of metal M is deposited at the cathode by passing 0.2 F of electricity through the solution of metal chlorides. The formula of the metal chloride is: (atomic mass of M = 57 g/mol)

The first order diffraction of X-rays from a certain set of crystal planes occur at an angle of 11.8∘ from the planes. If the planes are 281 pm apart, what is the wavelength of X-rays (sin 11.8∘ = 0.2045)

Suppose the platform with the kid in the previous problem is rotating in anticlockwise direction at an angular speed ω. The kid starts walking along the rim with a speed v relative to the platform also in the anticlockwise direction. Find the new angular speed of the platform.

A man of height h walks in a straight path towards a lamp post of height H with velocity v. Then velocity of the edge of the shadow on the ground will be

In the circuit shown in figure switch S is closed at time t = 0. Let i1 and i2 be the currents at any finite time t then the ratio

A seconds metallic pendulum keeps correct time at 0∘ C. If it loses 12.5 s a day at 25∘ C, the coefficient of linear expansion of metal pendulum is

In the given figure , a=10√2 m/s2 represents the total acceleration of a particle moving in the clockwise direction in a circle of radius R=2 m at a given instant of time. Speed of the particle is

In a resonance tube experiment when a tuning fork of frequency 500 Hz is sounded over it, the first and second resonances are obtained at 17 cm and 52cm. the velocity of sound is Ans is 350 m/s. Please give detailed explanation as I won't be able to understand concise answers.

What is the effect of temperature on elasticity ? State reason .

A particle in a certain consevative force field has a potential energy given by U=20xyz. The force exerted on it is

Find the power of a pump which takes 10 s to draw 100 kg of water from a tank situated at a height of 20 m. (correct answer + 1, wrong answer - 0.25)

A longitudinal wave is represented by x=x0 sin 2π(nt−xλ). The maximum particle velocity will be four times the wave velocity if:

Write a schematic diagram of a single slit diffraction experiment and write condition for minima and secondary maxima.

A rod PQ of length ℓ is rotating with angular velocity ω about its mid-point, in a uniform magnetic field B which is perpendicular to the plane of rotation of the rod. Find the induced emf between PQ. ?

When the kinetic energy of a body executing SHM is 1/3 of the potential energy. The displacement of the body is x percent of the amplitude, where x is a.) 33 b.) 87 c.) 67 d.) 50

An ideal gas is kept inside a 4 L container at a temperature of 300 k and a pressure of 6 atmospheres. If the pressure is held constant while the volume of the gas is doubled, then find out the new temperature of the gas.

What is the significance of rms velocity of gas molecules?

In the circuit shown in figure, cells of emf 2,1,3 and 1 V, respectively and resistances 2 Ω,1 Ω,3 Ω and 1 Ω are their internal resistances respectively. The potential difference between D and B is given as n13 volts. Find n.

An electro-magnetic wave in vacuum has the electric and magnetic fields as ¯E and ¯B , which are always perpendicular to each other. The direction of polarization is given by ¯X and that of the wave propagation as ¯k. Then

In the given figure a =15 m/s2 represents the total acceleration of a particle moving in clockwise direction in a circle of radius R = 2.5m at a given instant of time. The speed of the particle is:

A car is moving in a rainstorm at a speed of 60 km/h. The rain drops fall vertically w.r.t the ground with a constant speed of 15 m/s. The angle with the vertical at which raindrops strike the car is

An inductor (L=0.03 H) and a resistor (R=0.15 kΩ) are connected in series to a battery of 15 V emf in a circuit shown below. The key K1 has been kept closed for a long time. Then at t=0,K1 is opened and key K2 is closed simultaneously. At t=1 ms, the current in the circuit will be (e5≅150)

In sound waves,a displacement node is a pressure antinode snd vice versa.Explain why?

Length l and Acceleration due to gravity g are measured with ± 6 % and ± 4 % errors respectively. The percentage error in determination of the Time period of a simple pendulum will be,

The figure shows a block of mass m placed on a smooth wedge of mass M. The value of M' is just sufficient, so that the block of mass m moves vertically downwards with acceleration 10 m/s2. Chose the correct option:

Find the velocity at the highest point, if it's projected with a speed 15ms^-1, in the direction 45° above the horizontal. Take g = 10 ms^-2

an elastic spring of unstretched lenght L and force constant K is stretched by a small length C it is further stretched by a small length Y the qork done in seconh stretching is

How long after the beginning of motion is the displacement of a harmonically oscillating point equal to one half its amplitude,if the period is 24 sec and initial phase is zero?

Two pith balls, each carrying charge +q are hung from a hook by two strings. It is found that when each charge is tripled, angle between the strings double. What was the initial angle between the strings?

A body of mass 8m is kept in X−Y plane at rest. If it suddenly explodes into three pieces with two of them moving perpendicular to each other at equal speeds, the kinetic energy generated during explosion is (refer figure)

A simple pendulum is carried at a depth of 1 km below sea level. It becomes

A rope of mass m0 and length L is suspended vertically. If a mass m is suspended from the bottom of the rope, find the time for a transverse wave to travel the length of the rope.