Physics Test 25...

The engine of a motorboat is switched off when its speed is v0. If motorboat experiences variable acceleration as dv/dt = −βv³, where β is a positive constant and v instantaneous speed, then the speed of motorboat after t second (t = 0 when switch is off) is

In a photodiode, the conductivity increases when the material is exposed to light. It is found that conductivity changes only if the wavelength is less than 600 nm. What is the bandgap?

If the magnetic dipole moment of an atom of diamagnetic material, paramagnetic material and ferromagnetic material is denoted by μ_d, μ_p and μ_f respectively, then

Which of the following will pair up to produce stationary wave?

(1) Z₁ = A cos(kx − ωt)
(2) Z₂ = A cos(kx + ωt)
(3) Z₃ = A cos(ky − ωt)
(4) Z₄ = A cos(kz + ωt)

A particle is undergoing SHM. Displacement vs time curve is as shown in the figure.

Match List - I (Electromagnetic wave type) with List - II (Its association/application) and select the correct option from the choices given below the lists :

Figure shows a cyclic process ABCDBEA performed on an ideal cycle. If P_A = 2 atm, P_B = 5 atm and P_C = 6 atm, V_E – V_A = 20 litre, find the work done (in KJ) by the gas in the complete process. (1 atm. pressure = 1 × 10⁵ Pa)

In the circuit shown, the key (K) is closed at t = 0, the current through the key at the t = 10⁻³ln² s; is.

If first excitation potential of a hydrogen like atom is V electron volt, then the ionization energy of this atom will be:

Let ω is the angular velocity of the earth's rotation about its own axis and acceleration due to gravity on the earth's surface at the poles is g. An object weighed by a spring balance gives the same reading at the equator, as well as at a height h above the poles (h ≪ R). What is the value of h ?