MHT - CET MCQ

After 1 hour, `(1/8)^"th"` of the initial mass of a certain radioactive isotope remains undecayed. The half-life of the isotopes is ______.

The radius of germanium (Ge) nuclide is measured to be twice the radius of `""^9""_4"Be"`. The number of nucleons in Ge will be ____________.

When an electron in hydrogen atom jumps from third excited state to the ground state, the de-Broglie wavelength associated with the electron becomes ____________.

Which of the following models was successful in explaining the observed hydrogen spectrum?

According to Rutherford's model of an atom, ______

An electron of mass m and a photon have same energy E. The ratio of de-Broglie wavelengths associated with them is ( c being velocity of light) ______.

When light of wavelength '`lambda`' is incident on photosensitive surface, photons of power 'P' are emitted. The number of photons (n) emitted in 't' second is (h = Planck's constant, c = velocity of light in vacuum) ____________.

In series resonance, LCR circuit, below the resonant frequency, the circuit is ____________.

In series 'LR' circuit and in series 'RC' circuit, same current is flowing. If the frequency of e.m.f. of a.c. is increased for both the circuits, the impedance will ____________.

In a series LCR circuit R = 300 Ω, L = 0.9 H, C = 2 µF, ω = 1000 rad/s. The impedance of the circuit is ______

Magnetic flux of 12 microweber is linked with a coil. When current of 3 mA flows through it, the self inductance of the coil is ____________.

The magnetic property of magnetic substance is associated with ____________.

Magnetic dipole moment `vec"m"` of the coil, placed in uniform magnetic field of induction `vec"B"` does not depend on ____________.

A straight wire of length 50 cm carrying a current of 6 A is suspended in mid-air by a uniform magnetic field of 0.4 T (as shown in figure). The mass of the wire is ______.

(g = 10` "ms"^-2`)

A galvanometer of resistance 100 Ω is connected to a battery of 2V, with a resistance of 1900 Ω in series. The deflection obtained is 30 divisions. To reduce this deflection by 10 divisions, the additional resistance required to be connected in series is ______

To convert galvanometer into an ammeter one has to connect ____________.

A potentiometer wire of length 100 cm has a resistance of 10 `Omega.` It is connected in series with a resistance and an accumulator of e.m.f 2 V and of negligible internal resistance. A source of e.m.f 10 mV is balanced against a 40 cm length of the potentiometer wire. The value of the external resistance is ____________.

ln, a Wheatstone network, P = Q = R = 8 `Omega` and S is 10 `Omega`. The required resistance to be connected to S so that network is balanced is ______.

A beam of light of wavelength 600 nm from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 4 m away. The distance between the first dark fringes on either side of the central bright fringe is ______.

The graph shows the variation of fringe width (β) versus distance of the screen from the plane of the slits (D) in Young's double-slit experiment Keeping other parameters the same. The wavelength of light used can be calculated as d = distance between the slits ______ 

For a radiation of 9 GHz passing through air. The number of waves passing through 1 m length is ____________.

In melde's experiment, when the tension decreases by 0.009 kg-wt, the number of loops changes from 4 to 5. The initial tension is ______.

The amplitude of a wave represented by equation `"y" = 1/(sqrt"a") "sin" omega"t" pm 1/(sqrt"b") "cos" omega"t"` will be ____________.

An `alpha` - particle of energy 5 MeV is scattered through 180° by gold nucleus. The distance of closest approach is of the order of ______.

If the length of an oscillating simple pendulum is made `1/3` times at a place keeping amplitude the same, then its total energy (E) will be ______

The pointer reading v/s load graph for a spring balance is as given in the figure. The spring constant is ______. 

Given that 'p' joule of heat is incident on a body and out of it 'q' joule is reflected and transmitted by it. The absorption coefficient of the body is ____________.

The average K.E. of hydrogen molecules at 27° C is E. The average K.E. at 627° C is ____________.

A metal coin of thickness 'd' and density 'ρ' is floating on water of surface tension 'T'. The radius of the coin is ______.

g = acceleration due to gravity

When a mercury drop of radius 'R', breaks into 'n' droplets of equal size, the radius 'r' of each droplet is ______.

A motorcyclist rides in a horizontal circle about central vertical axis inside a cylindrical chamber of radius 'r'. If the coefficient of friction between the tyres and the inner surface of chamber is 'µ', the minimum speed of motorcyclist to prevent him from skidding is ______.

('g' =acceleration due to gravity)

In insulators, ____________.

A point object is placed at a distance of 25 cm from a convex mirror of focal length 25 cm. The image will form at ____________.

Assertion: The change in air pressure affects the speed of sound.

Reason: The speed of sound in gases is proportional to the square of pressure.

In a closed pipe, the note of fundamental frequency can be produced if the length of the air column is equal to ____________.

1 litre of an ideal gas at 27 °C is heated at a constant pressure to 127 °C. The final volume is approximately ______.

If the Earth-Sun distance is held constant and the mass of the Sun is doubled, then the period of revolution of the earth around the Sun will change to ____________.

5 m long see-saw remains horizontal when two children weighing 20 kg and 30 kg respectively sit at two ends. Where is the see-saw supported?