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Two identical conducting spheres with negligible volume

Two identical conducting spheres with negligible volume have 2.1nC and -0.1nC charges, respectively. They are brought into contact and then... View Article

The peak electric field produced by the radiation coming from the 8 W bulb at a distance of 10 m is (x/10) √(µ₀c/π) V/m. The efficiency of the bulb is 10% and it is a point source. The value of x is ___.

Answer: 2 Intensity I = ½ c∈0E02 Intensity = Power / Area = 8 /(4π × 102) (8/4π×102) ×½ =¼... View Article

Two small spheres each of mass 10 mg are suspended from a point by threads 0.5 m long.

Two small spheres each of mass 10 mg are suspended from a point by threads 0.5 m long. They are equally charged and repel each other to a... View Article

The percentage increase in the speed of transverse waves produced in a stretched string if the tension is increased by 4% will be ___%.

Answer: 2 Speed of transverse wave is V = √(T/μ) Taking log on both sides ln v = ½ lnT - ½ ln μ Δv/v =... View Article

If e is the electronic charged, c is the speed of light in free space and h is planck’s constant, the quantity (1/4πε₀) |e|²/hc has dimensions of:

a.[ LC-1] b. [M0 L0 T0] c. [ M L T0] d. [M L T-1] Answer: (b) Given e = electronic charge c = speed of light in free space h = planck's constant... View Article

The truth table for the following logic circuit is:

The truth table for the following logic circuit is: Answer: (4) If A = B = 0 then output y = 1 If A = B = 1 then output y = 1... View Article

An LCR circuit contains resistance of 110 Ω and a supply of 220 V at 300 rad/s angular frequency.

An LCR circuit contains resistance of 110 Ω and a supply of 220 V at 300 rad/s angular frequency. If only capacitance is removed from the... View Article

An electron with kinetic energy

An electron with kinetic energy K1 enters between parallel plates of a capacitor at an angle 'α’ with the plates. It leaves the... View Article

Given below are two statements:

Given below are two statements: Statement I: In a diatomic molecule, the rotational energy at a given temperature obeys Maxwell's distribution.... View Article

If a message signal of frequency ‘f_m‘ is amplitude modulated with a carrier signal of frequency ‘f_c‘ and radiated through an antenna, the wavelength of the corresponding signal in air is:

[Given, C is the speed of electromagnetic waves in vacuum/air] a. c/(fc+fm) b. c/(fc-fm) c. c/fm d. c/fc Answer: (d) Equation of amplitude... View Article

A stone is dropped from the top of a building. When it crosses a point 5m below the top, another stone starts to fall from a point 25m below the top, both stones reach the bottom of building simultaneously. The height of the building is: [Take g = 10 m/s²]

a. 45 m b. 35 m c. 25 m d. 50 m Answer: (a) Velocity of particle (1) at 5m below top u1 = √2gh = √(2×10×5) =10 m/s... View Article

Thermodynamic process is shown below on a P-V diagram

Thermodynamic process is shown below on a P-V diagram for one mole of an ideal gas. If V2 = 2V1 then the ratio of temperature T2/T1 is: ... View Article

An electron of mass m_e and a proton of mass m_p = 1836 m_e are moving with the same speed. The ratio of their de Broglie wavelength λ_electron/λ_Proton will be:

a. 918 b. 1836 c. 1/1836 d. 1 Answer: (b) Given mass of electron = me Mass of proton = mp ∴ given mp = 1836 me From de-Broglie... View Article

Consider the diffraction pattern obtained from the sunlight incident on a pinhole of diameter 0.1 μm. If the diameter of the pinhole is slightly increased, it will affect the diffraction pattern such that:

a. its size decreases, but intensity increases b. its size increases, but intensity decreases c. its size increases, and intensity increases d.... View Article

A sphere of radius ‘a’ and mass ‘m’ rolls along horizontal plane with constant speed v₀.

A sphere of radius 'a' and mass 'm' rolls along horizontal plane with constant speed v0. It encounters an inclined plane at angle θ and... View Article

A charge ‘q’ is placed at one corner of a cube as shown in figure.

A charge 'q' is placed at one corner of a cube as shown in figure. The flux of electrostatic field through the shaded area is: a.... View Article

The stopping potential for electrons emitted from a photosensitive surface illuminated by light of wavelength 491 nm is 0.710 V. When the incident wavelength is changed to a new value, the stopping potential is 1.43 V. The new wavelength is:

a. 400 nm b. 382 nm c. 309 nm d. 329 nm Answer: (b) From the photoelectric effect equation hc/λ = ϕ + evs where Vs is the stopping... View Article

The point A moves with a uniform speed along the circumference of a circle of radius 0.36m and cover 30^o in 0.1s.

The point A moves with a uniform speed along the circumference of a circle of radius 0.36m and cover 30o in 0.1s. The perpendicular projection... View Article

In a ferromagnetic material below the Curie temperature, a domain is defined as:

a. a macroscopic region with consecutive magnetic diploes oriented in opposite direction. b. a macroscopic region with zero magnetization. c. a... View Article

The wavelength of the photon emitted by a hydrogen atom when an electron makes a transition from n = 2 to n = 1 state is:

a. 194.8 nm b. 490.7 nm c. 913.3 nm d. 121.8 nm Answer: (d) ∆E = 10.2 eV is the energy difference between the state n = 2 & n = 1 ∆E =... View Article