List of top Questions asked in MHT CET

Two radioactive substances \(A\) and \(B\) have decay constant \(5\lambda\) and \(\lambda\) respectively. At \(t=0\), they have the same number of nuclei. The ratio of number of nuclei of \(A\) to those of \(B\) will be \(\left(\frac{1}{e}\right)^{2}\) after a time interval
The following circuit is equivalent to
In an n-p-n transistor the collector current is \(9\) mA. If \(90\%\) of the electrons from the emitter reach the collector then
Calculate the number of atoms in each of the following.
(a) \(11.2\) g nitrogen (b) \(1.15\) g sodium
A double slit experiment is performed with light of wavelength \(500\) nm. A thin film of thickness \(2\) \(\mu\)m and refractive index \(1.5\) is introduced in the path of the upper beam. The location of the central maximum
In double slit experiment, the two slits are \(1\) mm apart and the screen is placed \(1\) m away. A monochromatic light of wavelength \(500\) nm is used. What will be the width of each slit for obtaining ten maxima of double slit within the central maxima of single slit pattern?
A point source of light is used in a photoelectric effect. If the source is moved farther from the emitting metal, then the stopping potential
When an electron in hydrogen atom revolves in a stationary orbit, it
The energy of a photon is equal to the kinetic energy of a proton. If \(\lambda _{1}\) is the de-Broglie wavelength of a proton, \(\lambda _{2}\) is the wavelength associated with the photon and if the energy of the photon is \(E\) then \((\lambda _{1}/\lambda _{2})\) is proportional to
Two coherent sources \(P\) and \(Q\) produce interference at a point \(A\) on the screen where there is a dark band which is formed between \(4^{\text{th}}\) bright band and \(5^{\text{th}}\) bright band. Wavelength of light used is \(6000\) Å. The path difference between \(PA\) and \(QA\) is \(x\times 10^{-4}\) cm. The value of \(x\) is
A coil of wire of radius \(r\) has \(600\) turns and a self-inductance of \(108\) mH. The self inductance of a coil with same radius and \(500\) turns is
An inductance of negligible resistance, whose reactance is \(120\) \(\Omega\) at \(200\) Hz is connected to a \(240\) V, \(60\) Hz Power line. The current in the inductor is
How much water should be filled in a container of height \(21\) cm, so that it appears half filled to the observer when viewed from the top of the container? (\(\mu =4/3\))
An alternating voltage \(V=200\sqrt{2}\sin (100t)\) volt is connected to a \(1\) \(\mu\)F capacitor through an a.c. ammeter. The reading of the ammeter will be
In an a.c. circuit, if the power factor changes from \(0.5\) to \(0.25\) then the increase in impedance is
A step down transformer has \(50\) turns on secondary and \(1000\) turns on primary winding. If a transformer is connected to \(220\) V and \(1\) A a.c. source, what is the output current of the transformer?
The magnitude of the magnetic field inside a long solenoid is increased by
A domain in a ferromagnetic substance is in the form of a cube of side '\(L\)'. If it contains '\(N\)' atoms and each atomic dipole moment \(M\) then the magnetisation of the domain is
An ammeter has resistance \(R\) and range \(I\). What resistance should be connected in parallel with it to increase its range by \(nI\)?
A varying magnetic flux linking a coil is \(\Phi =xt^{2}\). If at time \(t=3\) s, the e.m.f. induced is \(9\)V then the magnitude of \(x\) is (in \(\text{Wb}/\text{s}^{2}\))
Two circular coils \(A\) and \(B\) are made from the same wire but the radius of coil \(A\) is twice that of coil \(B\). What is the ratio of potential difference applied across them, so that the magnetic field at their centres is the same?
A slab of material of dielectric constant \(k\) has the same area as the plates of the parallel plate capacitor but has thickness \(\frac{3d}{4}\), where \(d\) is the separation of the plates. How is the capacitance changed, when the slab is inserted between the plates? (\(C\) = original capacitance)
A current of \(0.01\) A passes through the potentiometer wire of resistivity \(10^{6}\) \(\Omega\) cm and area of cross-section \(10^{-2}\) \(\text{cm}^{2}\). The potential gradient is (in V/m)
Charge \(q_{2}\) of mass '\(m\)' revolves around a stationary charge \(q_{1}\) in a circular orbit of radius '\(r\)'. The orbital periodic time of \(q_{2}\) would be \(\left(k=\frac{1}{4\pi \epsilon _{0}}\right)\)
Two sirens situated one km apart are producing sound of frequency \(330\) Hz. The observer starts moving from one siren to the other with a speed of \(2\) m/s. If the speed of sound is \(330\) m/s, What will be the beat frequency heard by the observer?