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This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A particle of mass m moving towards west with a speed v collides with another particle of mass m moving towards south. If two particles stick to each other the speed of the new particle of mass 2m will be? |
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Answer» A particle of mass m moving towards west with a speed v collides with another particle of mass m moving towards south. If two particles stick to each other the speed of the new particle of mass 2m will be? |
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| 2. |
Excitation energy of a hydrogen like ion in its first excitation state is 40.8 eV. Energy needed to remove the electron from the ion in ground state is |
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Answer» Excitation energy of a hydrogen like ion in its first excitation state is 40.8 eV. Energy needed to remove the electron from the ion in ground state is |
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| 3. |
Figure shows, two equipotential surfaces V1 and V2. The component of electric field (in SI units) along x and y direction will be - |
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Answer» Figure shows, two equipotential surfaces V1 and V2. The component of electric field (in SI units) along x and y direction will be - |
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| 4. |
Who was Planck and what is rydeberg equation and photoelectric effect |
| Answer» Who was Planck and what is rydeberg equation and photoelectric effect | |
| 5. |
25.Glass lens of refractive index 1.5 of focal length 20cm in air is dipped in water(refractive index=4/3). New focal length of the lens inside water is |
| Answer» 25.Glass lens of refractive index 1.5 of focal length 20cm in air is dipped in water(refractive index=4/3). New focal length of the lens inside water is | |
| 6. |
The lower end of a capillary tube is immersed in mercury. The level of mercury in the tube is found to be 2 cm below the outer level. If the same tube is immersed in water, up to what height will the water rise in the capillary? |
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Answer» The lower end of a capillary tube is immersed in mercury. The level of mercury in the tube is found to be 2 cm below the outer level. If the same tube is immersed in water, up to what height will the water rise in the capillary? |
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| 7. |
If two capillary tubes of radii r1 and r2 in the ratio 1:2 are dipped vertically in water, then the ratio of capillary rises in the respective tubes is |
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Answer» If two capillary tubes of radii r1 and r2 in the ratio 1:2 are dipped vertically in water, then the ratio of capillary rises in the respective tubes is |
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| 8. |
A slit 4.0cm wide is irradiated with microwaves of wavelength 2.0cm . Find the angular spread of central maxima assuming incidence normal to the plane of the slit. |
| Answer» A slit 4.0cm wide is irradiated with microwaves of wavelength 2.0cm . Find the angular spread of central maxima assuming incidence normal to the plane of the slit. | |
| 9. |
A cosmic body A moves to the sun with velocity v0 (when far from the sun) and aimimg parmeter l the arm of the vector →v0 relative to the center of the sun. Find the minimum distance by which this body will get to the Sun. Mass of the Sun is M. |
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Answer» A cosmic body A moves to the sun with velocity v0 (when far from the sun) and aimimg parmeter l the arm of the vector →v0 relative to the center of the sun. Find the minimum distance by which this body will get to the Sun. Mass of the Sun is M. |
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| 10. |
Two plane mirrors are inclined to each other at an angle of 70∘ as shown in figure. A ray of light PO incident at some angle i on the mirror M1 falls on the other mirror M2 after reflection, and also becomes parallel to the plane mirror M1 after another reflection. Find the value of i. |
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Answer» Two plane mirrors are inclined to each other at an angle of 70∘ as shown in figure. A ray of light PO incident at some angle i on the mirror M1 falls on the other mirror M2 after reflection, and also becomes parallel to the plane mirror M1 after another reflection. Find the value of i.
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| 11. |
76.a system of mass 1kg in motion along the x-axis is given by U=4[1-cos2x] joule, where x in meter . The period of small oscillation (in sec) is. |
| Answer» 76.a system of mass 1kg in motion along the x-axis is given by U=4[1-cos2x] joule, where x in meter . The period of small oscillation (in sec) is. | |
| 12. |
Two large circular discs separated by a distance of 0.01 m are connected to a battery via a switch as shown in the figure. Charged oil drops of density 900 kg m−3 are released through a tiny hole at the center of the top disc. Once some oil drops achieve terminal velocity, the switch is closed to apply a voltage of 200 V across the discs. As a result, an oil drop of radius 8×10−7 m stops moving vertically and floats between the discs. The number of electrons present in this oil drop is ______. (neglect the buoyancy force, take acceleration due to gravity =10 ms−2 and charge on an electron (e)=1.6×10−19 C) |
Answer» Two large circular discs separated by a distance of 0.01 m are connected to a battery via a switch as shown in the figure. Charged oil drops of density 900 kg m−3 are released through a tiny hole at the center of the top disc. Once some oil drops achieve terminal velocity, the switch is closed to apply a voltage of 200 V across the discs. As a result, an oil drop of radius 8×10−7 m stops moving vertically and floats between the discs. The number of electrons present in this oil drop is ______. (neglect the buoyancy force, take acceleration due to gravity =10 ms−2 and charge on an electron (e)=1.6×10−19 C) |
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| 13. |
A radioactive isotope is being produced at a constant rate X. Half-life of the radioactive substance is Y. After some time, the number of radioactive nuclei become constant. The value of this constant is |
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Answer» A radioactive isotope is being produced at a constant rate X. Half-life of the radioactive substance is Y. After some time, the number of radioactive nuclei become constant. The value of this constant is |
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| 14. |
Charge passes through a conductor of cross section at area A=0.3m2 is given by q=3t2+5t+2 in coloumb, where t is in second. What is the value of drift velocity at t = 2 sec (given n = 2×1025/m2)? |
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Answer» Charge passes through a conductor of cross section at area A=0.3m2 is given by q=3t2+5t+2 in coloumb, where t is in second. What is the value of drift velocity at t = 2 sec (given n = 2×1025/m2)? |
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| 15. |
A bus starts moving with acceleration 2 ms−2. A cyclist 96 m behind the bus starts simultaneously towards the bus at a constant speed of 20 m/s. After what minimum time will he be able to overtake the bus? |
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Answer» A bus starts moving with acceleration 2 ms−2. A cyclist 96 m behind the bus starts simultaneously towards the bus at a constant speed of 20 m/s. After what minimum time will he be able to overtake the bus? |
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| 16. |
A football is kicked at an angle θ = 45∘. It is intended that the ball lands in the back of a moving truck, which has a trunk of length L = 5 m. If the initial horizontal distance from the back of the truck to the ball, at the instant of the kick is 5 m & the truck moves directly away from the ball at velocity V = 9 m/s. What is approximate maximum & minimum velocity (in m/s) so that ball lands on the truck? (Assume the ball & back of the truck to be at the same horizontal level) |
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Answer» A football is kicked at an angle θ = 45∘. It is intended that the ball lands in the back of a moving truck, which has a trunk of length L = 5 m. If the initial horizontal distance from the back of the truck to the ball, at the instant of the kick is 5 m & the truck moves directly away from the ball at velocity V = 9 m/s. What is approximate maximum & minimum velocity (in m/s) so that ball lands on the truck? (Assume the ball & back of the truck to be at the same horizontal level) |
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| 17. |
How fast a person should drive his car so that the beam at wavelength 480nm is observed at 480.08nm?? |
| Answer» How fast a person should drive his car so that the beam at wavelength 480nm is observed at 480.08nm?? | |
| 18. |
Consider the following two statements:(A) Linear momentum of the system remians constant.(B) Centre of mass of the system remains at rest. |
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Answer» Consider the following two statements: |
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| 19. |
Find the relation between acceleration of A(a) and acceleration of B(b) in the figure shown |
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Answer» Find the relation between acceleration of A(a) and acceleration of B(b) in the figure shown |
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| 20. |
Two blocks of 4 kg and 6 kg are attached by springs and they are hanging in vertical position. Lower spring breaks due to excessive force. Acceleration of 4 kg block just after breaking will be (Take g=10 m/s2) |
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Answer» Two blocks of 4 kg and 6 kg are attached by springs and they are hanging in vertical position. Lower spring breaks due to excessive force. Acceleration of 4 kg block just after breaking will be (Take g=10 m/s2) |
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| 21. |
A solid metallic cylinder carries a direct current. The magnetic field produced by it exists |
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Answer» A solid metallic cylinder carries a direct current. The magnetic field produced by it exists |
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| 22. |
How many Alvars come from divergent backgrounds? |
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Answer» How many Alvars come from divergent backgrounds? |
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| 23. |
Moment of inertia of a thin rod of mass M and length L about an axis passing through centre is ML2/12. Its moment of inertia about a parallel axis at a distance of L/4 from the axis is given by? A. ML2/48 B. ML3/48 C. ML2/12 D. 7ML2/48 |
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Answer» Moment of inertia of a thin rod of mass M and length L about an axis passing through centre is ML2/12. Its moment of inertia about a parallel axis at a distance of L/4 from the axis is given by? A. ML2/48 B. ML3/48 C. ML2/12 D. 7ML2/48 |
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| 24. |
A particle moving on x-axis has potential energy, u=(2−20x+5x2) J along x-axis. The particle is released at x=−3.The maximum value of x in m will be |
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Answer» A particle moving on x-axis has potential energy, u=(2−20x+5x2) J along x-axis. The particle is released at x=−3.The maximum value of x in m will be |
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| 25. |
what is displacement current actually |
| Answer» what is displacement current actually | |
| 26. |
A lead bar of length 50 cm and square cross-section of side 5 cm is fixed to a vertical wall as shown in figure. A massless tank is suspended from the end of the bar with the help of a massless rope. The tank is slowly filled with mercury at room temperature. Find the level of mercury in the tank so that the end of the bar deviates by 1 mm. [Take modulus of rigidity for lead as 5.6 Gpa and area of base of cylindrical tank as 0.42 m2;ρHg=13600 kg/m3 & g=9.8 m/s2] |
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Answer» A lead bar of length 50 cm and square cross-section of side 5 cm is fixed to a vertical wall as shown in figure. A massless tank is suspended from the end of the bar with the help of a massless rope. The tank is slowly filled with mercury at room temperature. Find the level of mercury in the tank so that the end of the bar deviates by 1 mm. |
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| 27. |
A long string with a charge of λ per unit length passes through an imaginary cube of edge l. The maximum possible flux of the electric field through the cube will be |
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Answer» A long string with a charge of λ per unit length passes through an imaginary cube of edge l. The maximum possible flux of the electric field through the cube will be |
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| 28. |
A 10 H inductor carries a current of 20 A. How much ice at 0 ∘C could be melted by the energy stored in the magnetic field of the inductor. Latent heat of fusion of ice is 3.4×105 J/Kg. |
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Answer» A 10 H inductor carries a current of 20 A. How much ice at 0 ∘C could be melted by the energy stored in the magnetic field of the inductor. Latent heat of fusion of ice is 3.4×105 J/Kg. |
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| 29. |
Three charges each q are kept at 3 corners of a square as shown in fig and q /2 is at one corner . Electric field at the centre is |
| Answer» Three charges each q are kept at 3 corners of a square as shown in fig and q /2 is at one corner . Electric field at the centre is | |
| 30. |
A moving-coil galvanometer has 100 turns and each turn has an area 2.0 cm2. The magnetic field produced by the magnet is 0.01 T. The deflection in the coil is 0.05 radian when a current of 10 mA is passed through it. Find the torsional constant of the suspension wire. |
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Answer» A moving-coil galvanometer has 100 turns and each turn has an area 2.0 cm2. The magnetic field produced by the magnet is 0.01 T. The deflection in the coil is 0.05 radian when a current of 10 mA is passed through it. Find the torsional constant of the suspension wire. |
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| 31. |
Two stones are thrown up simultaneously from the edge of a cliff 200 m high with initial speeds of 15 m s¯¹ and 30 m s¯¹. Verify that the graph shown in Fig. 3.27 correctly represents the time variation of the relative position of the second stone with respect to the first. Neglect air resistance and assume that the stones do not rebound after hitting the ground. Take g = 10 m s¯². Give the equations for the linear and curved parts of the plot. |
| Answer» Two stones are thrown up simultaneously from the edge of a cliff 200 m high with initial speeds of 15 m s¯¹ and 30 m s¯¹. Verify that the graph shown in Fig. 3.27 correctly represents the time variation of the relative position of the second stone with respect to the first. Neglect air resistance and assume that the stones do not rebound after hitting the ground. Take g = 10 m s¯². Give the equations for the linear and curved parts of the plot. | |
| 32. |
A long conveyor belt is designed to transport packages of various weights. Each 20 kg package has a coefficient of kinetic friction 0.25. If the speed of the conveyor belt is 10 m/s and then it suddenly stops, the distance the package will slide before coming to rest is |
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Answer» A long conveyor belt is designed to transport packages of various weights. Each 20 kg package has a coefficient of kinetic friction 0.25. If the speed of the conveyor belt is 10 m/s and then it suddenly stops, the distance the package will slide before coming to rest is |
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| 33. |
I have a battery of internal resistance 20mΩ. When discharging with a current of 1A, the potential difference across its terminals is 2V. What is its EMF? |
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Answer» I have a battery of internal resistance 20mΩ. When discharging with a current of 1A, the potential difference across its terminals is 2V. What is its EMF? |
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| 34. |
What does a velocity -distance graph gives us? |
| Answer» What does a velocity -distance graph gives us? | |
| 35. |
In the figure shown, the coefficient of static friction between B and the wall is 23 and the coefficient of kinetic friction between B and the wall is 13. Other contacts are smooth. If the minimum force ′F′ required to lift B up is xmg2, then find x. Mass of A is 2m and the mass of B is m. Take tanθ=34. |
Answer» In the figure shown, the coefficient of static friction between B and the wall is 23 and the coefficient of kinetic friction between B and the wall is 13. Other contacts are smooth. If the minimum force ′F′ required to lift B up is xmg2, then find x. Mass of A is 2m and the mass of B is m. Take tanθ=34.  |
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| 36. |
2.To get equilibrium of three point charges 1) they should be collinear and of same nature. 2) they should be collinear and different in nature. 3) they must lie on vertices of equilateral triangle. 4) they must be of same nature Which opt is correct and why? |
| Answer» 2.To get equilibrium of three point charges 1) they should be collinear and of same nature. 2) they should be collinear and different in nature. 3) they must lie on vertices of equilateral triangle. 4) they must be of same nature Which opt is correct and why? | |
| 37. |
A circular race track of radius 85 m is banked at angle of 37∘ If the coefficient of friction between the wheels of a race-car and the road is 0.2, then the maximum possible speed to avoid slipping is (tan 37∘=34) |
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Answer» A circular race track of radius 85 m is banked at angle of 37∘ If the coefficient of friction between the wheels of a race-car and the road is 0.2, then the maximum possible speed to avoid slipping is (tan 37∘=34) |
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| 38. |
A 20 V, 50 Hz AC source is connected across a resistor of resistance R and a capacitor of capacitance C as shown in the figure. The voltage across the resistor is 12 V. The voltage across the capacitor is |
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Answer» A 20 V, 50 Hz AC source is connected across a resistor of resistance R and a capacitor of capacitance C as shown in the figure. The voltage across the resistor is 12 V. The voltage across the capacitor is |
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| 39. |
The ionization potential of the ground state of a hydrogen atom is 2.17×10−11 ergs per atom. What would be the wavelength of a photon that is emitted when an electron from the 3rd Bohr orbit returns to the 1st orbit in the hydrogen atom? |
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Answer» The ionization potential of the ground state of a hydrogen atom is 2.17×10−11 ergs per atom. What would be the wavelength of a photon that is emitted when an electron from the 3rd Bohr orbit returns to the 1st orbit in the hydrogen atom? |
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| 40. |
What is law of conservation of angular and linear momentum? |
| Answer» What is law of conservation of angular and linear momentum? | |
| 41. |
A spherical charged conductor of radius 5cm is given a charge of 20 nue . what is the value of electric field at a distance if 1m from the center if the conductor? ( E knot =8.85×10^-12 SI unit) |
| Answer» A spherical charged conductor of radius 5cm is given a charge of 20 nue . what is the value of electric field at a distance if 1m from the center if the conductor? ( E knot =8.85×10^-12 SI unit) | |
| 42. |
The position x of a particle varies with time as x² = t² + 1. Then acceleration of particle is________ |
| Answer» The position x of a particle varies with time as x² = t² + 1. Then acceleration of particle is________ | |
| 43. |
The electrical resistance in ohms of a certain thermometer varies with temperature according to the approximate law : R = Rₒ [1 + α (T – Tₒ )] The resistance is 101.6 W at the triple-point of water 273.16 K, and 165.5 W at the normal melting point of lead (600.5 K). What is the temperature when the resistance is 123.4 W |
| Answer» The electrical resistance in ohms of a certain thermometer varies with temperature according to the approximate law : R = Rₒ [1 + α (T – Tₒ )] The resistance is 101.6 W at the triple-point of water 273.16 K, and 165.5 W at the normal melting point of lead (600.5 K). What is the temperature when the resistance is 123.4 W | |
| 44. |
A concave mirror of radius of curvature R producesa real image n times the size of the object, then distance of the object from the mirror is (1) -2(n-1)R (2) (-(n-1)R)/2n (3)(-(n+1)R)/2n (4)(-(n+1)R)/2 |
| Answer» A concave mirror of radius of curvature R producesa real image n times the size of the object, then distance of the object from the mirror is (1) -2(n-1)R (2) (-(n-1)R)/2n (3)(-(n+1)R)/2n (4)(-(n+1)R)/2 | |
| 45. |
A mass-spring-dashpot system with mass m =10 kg, spring constant k = 6250 N/m is excited by a harmonic excitation of 10 cos(25t)N. At the steady state, the vibration amplitude of the mass is 40 mm. The damping coefficiend (c, in Ns/m) of the dashpot is |
Answer» A mass-spring-dashpot system with mass m =10 kg, spring constant k = 6250 N/m is excited by a harmonic excitation of 10 cos(25t)N. At the steady state, the vibration amplitude of the mass is 40 mm. The damping coefficiend (c, in Ns/m) of the dashpot is |
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| 46. |
21.Two point charges Aq and (1-A)q are placed r distance apart. Once A=A1 and then A=A2 if force remain same then a) A1+A2=1 B)A1+A2=2 C)A1A2+A2A2 =1 |
| Answer» 21.Two point charges Aq and (1-A)q are placed r distance apart. Once A=A1 and then A=A2 if force remain same then a) A1+A2=1 B)A1+A2=2 C)A1A2+A2A2 =1 | |
| 47. |
Foran amplitude modulated wave, the maximum amplitude isfound to be 10 V while the minimum amplitude is found to be 2 V.Determine the modulation index μ.What would be the value of μ ifthe minimum amplitude is zero volt? |
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Answer» For |
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| 48. |
A standing wave is produced in a 10 m long string fixed at one end and free at the other end. Find the wavelength of wave, if string is vibrating in its second overtone, and wave velocity is 20 m/s. |
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Answer» A standing wave is produced in a 10 m long string fixed at one end and free at the other end. Find the wavelength of wave, if string is vibrating in its second overtone, and wave velocity is 20 m/s. |
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| 49. |
A hollow shaft of 1 m length is designed to transmit a power of 30 kW at 700 rpm. The maximum permissibel angle of twist in the shaft is 10. The inner diameter of the shaft is 0.7 times the outer diameter. The modulus of rigidity is 80 GPa. The outside diameter (in mm) of the shaft is |
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Answer» A hollow shaft of 1 m length is designed to transmit a power of 30 kW at 700 rpm. The maximum permissibel angle of twist in the shaft is 10. The inner diameter of the shaft is 0.7 times the outer diameter. The modulus of rigidity is 80 GPa. The outside diameter (in mm) of the shaft is |
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| 50. |
If vectors x2^i+3^j+^k and ^i−x^j−(2m−9)^k makes acute angle for all values of x∈R, then the number of non-negative integral value(s) of m is |
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Answer» If vectors x2^i+3^j+^k and ^i−x^j−(2m−9)^k makes acute angle for all values of x∈R, then the number of non-negative integral value(s) of m is |
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