List of top Questions asked in MHT CET

Calculate the longest wavelength in the hydrogen emission spectrum of the Balmer series. [\(\tilde{v}=109677\ \text{cm}^{-1}\)]
Calculate the atomic mass in terms of \(u\) if the mass of an atom is \(4.9817\times 10^{-23}\) g.
[\(1\) amu = \(1.66056\times 10^{-24}\) g]
In an n-p-n transistor in common emitter configuration when \(V_{BE}\) is increased by small amount then
According to Huygens principle, a wave front propagates through a medium by
An electron of stationary hydrogen atom jumps from 4th energy level to ground level. The recoil velocity of the atom as a result of electron transition will be
(\(h\) = Planck's constant, \(R\) = Rydberg's constant, \(m=\text{mass of hydrogen atom}\))
A radioactive sample \(S_{1}\) having activity \(A_{1}\) has twice the number of nuclei as another sample of \(S_{2}\) of activity \(A_{2}\). If \(A_{2}=2A_{1}\) then the ratio of half life of \(S_{1}\) to the half life of \(S_{2}\) is
Light of wavelength \(\lambda\) strikes a photoelectric surface and electrons are ejected with an energy \(E\). If \(E\) is to be increased to exactly twice its original value, the wavelength changes to \(\lambda _{1}\) where
An electron of mass \(m\) and charge \(e\) initially at rest gets accelerated by a constant electric field \(E\). The rate of change of de-Broglie wavelength of the electron at time \(t\) is
(\(h\) = Planck's constant)
In double slit experiment, the angular width of the fringes is \(0.20^{\circ }\) for sodium light (\(\lambda =5890\ \text{Å}\)). To increase the angular width of the fringes by \(10\%\), the necessary change in wavelength is
In Young's experiment, one of the slit is covered with a transparent sheet of thickness \(3.6\times 10^{-3}\) cm due to which position of central image shifts to a position originally occupied by \(30^{th}\) bright fringe. The refractive index of the sheet is (\(\lambda =6000\ \text{Å}\))
An achromatic convergent doublet of two lenses in contact has a power of \(+2D\). The convex lens has power \(+5D\). What is the ratio of the dispersive powers of the convergent and divergent lenses?
If a transformer of an amplifier has output impedance \(8000\ \Omega\) and the speaker has input impedance of \(8\ \Omega\), the primary and secondary turns of this transformer connected between the output of amplifier and to loudspeaker should have the ratio
Which one of the following graph represents the correct variation of inductive reactance (\(X_{L}\)) with angular frequency (\(\omega\))?
A conducting rod AC of length \(4L\) is rotated counter-clockwise about a point O in a uniform magnetic field \(B\) directed into the paper. If \(AO=L\) and \(OC=3L\) then (\(\omega\) = angular speed)
The natural frequency of L-C circuit is \(125000\) Hz. Then the capacitor C is replaced by another capacitor with a dielectric medium of dielectric constant K. Now the frequency decreases by \(25\) KHz. The value of K is
A magnetising field of \(5000\) A/m produces a magnetic flux of \(4\times 10^{-5}\) Wb in an iron rod of cross-sectional area \(0.4\ \text{cm}^{2}\). The permeability of the rod (in Wb/Am) is
Two similar circular loops carry equal currents in the same direction. On moving coils further apart, the electric current will
An alternating voltage \(V=200\sqrt{2}\sin (100t)\) volt is connected to \(1\ \mu F\) capacitor through a.c. ammeter. The reading of ammeter is
Two circular coils A and B are made from same wire but the radius of coil A is twice that of coil B. If the magnetic field at their centres is same then the ratio potential difference applied across them is
When an electron is kept in a strong magnetic field, then
Potentiometer wire of length \(1\)m is connected in series with \(490\ \Omega\) resistance and \(2\) V battery. If \(0.2\) mV/cm is the potential gradient then the resistance of the potentiometer wire is
A charge \(10\ \mu C\) exists at the centre of a square. The work done in moving a \(2\ \mu C\) point charge from corner A to corner B of a square ABCD is
The electrostatic force (\(F\)) between the metal plates of an isolated parallel plate capacitor (\(C\)) having a charge \(Q\) and area \(A\) is (\(d\) = distance between the plates)
A resistor of \(6\ \Omega\) with a tolerance of \(10\%\) and another of \(4\ \Omega\) with a tolerance of \(10\%\) are connected in series. The tolerance of combination is about
With resistance \(x\) in the left gap and resistance \(9\ \Omega\) in right gap of a meter bridge, the balance point is obtained at \(40\) cm from left end. In what way and to which resistance \(3\ \Omega\) resistance be connected to obtain the balance point at \(50\) cm from the left end?