MAH-MHT CET (PCM/PCB) entrance exam Question Bank Solutions for Physics

Which one of the following is TRUE in photoelectric emission?

The following graph shows the stopping potential V₀ versus frequency v for photoelectric emission from two metals A and B. The slope of each of the lines gives ______

The radius of electron's second stationary orbit in Bohr's atom is R. The radius of the third orbit will be ______

Two identical bar magnets each of magnetic moment M, separated by some distance are kept perpendicular to each other. The magnetic induction at a point at the same distance d from the centre of magnets, is (µ₀ = permeability of free space)

When a photon enters glass from air, which one of the following quantity does not change?

A potentiometer wire is 4m long and potential difference of 3V is maintained between the ends. The emf of the cell, which balances against a length of 100 cm of the potentiometer wire is ____________.

For a particle performing SHM when displacement is x, the potential energy and restoring force acting on it is denoted by E and F, respectively. The relation between x, E and F is ____________.

Surface density of charge on a charged conducting sphere of radius R in terms of electric field intensity E at a distance r in free space is ____________.

(r > R, ε₀ = permittivity of free space)

The ratio of speed of an electron in the ground state in the Bohr's first orbit of hydrogen atom to velocity of light (c) is ____________.

(h = Planck's constant, ε₀ = permittivity of free space, e = charge on electron)

A moving body is covering distances which are proportional to square of the time. Then, the acceleration of the body is ____________.

The range of a projectile, when launched at an angle of 30° with the horizontal is 2 km. What is the range of the projectile, when launched at an angle of 45° with the horizontal?

A transverse wave is described by the equation, y = Y₀ sin 2π(ft - `"x"/lambda`). The maximum particle velocity is equal to four times the wave velocity if ______

A thermodynamic system goes from states (i) P, V to 2P, V  (ii) P, V to P, 2V. The work done in the two cases is ______.

The moment of inertia of a uniform thin rod of length L and mass M about an axis passing through a point at a distance of L/3 from one of its ends and perpendicular to the rod is ______

The graph of stopping potential `"V"_"s"` against frequency v of incident radiation is plotted for two different metals P and Q as shown in the graph. Φ_P and Φ_Q are work-functions of P and Q respectively, then

When light falls on a metal surface, the maximum kinetic energy of the emitted photoelectrons depends upon ______

If the maximum kinetic energy of emitted electrons in photoelectric effect is 3.2 × 10^-19 J and the work-function for metal is 6.63 × 10^-19 J, then stopping potential and threshold wavelength respectively are
[Planck's constant, h = 6.63 × 10³⁴ J-s]
[Velocity of light, c = 3 × 10⁸ `"m"/"s"`]
[Charge on electron= 1.6 × 10^-19 C]

Two cells having unknown emfs E₁ and E₂ (E₁ > E₂) are connected in potentiometer circuit, so as to assist each other. The null point obtained is at 490 cm from the higher potential end. When cell E₂ is connected, so as to oppose cell E₁, the null point is obtained at 90 cm from the same end. The ratio of the emfs of two cells `("E"_1/"E"_2)` is ______.

Three points masses, each of mass m are placed at the corners of an equilateral triangle of side l. The moment of inertia of the system about an axis passing through one of the vertices and parallel to the side joining other two vertices, will be ______.

Using Bohr's model, the orbital period of electron in hydrogen atom in nth orbit is (ε₀ = permittivity of free space, h = Planck's constant, m = mass of electron and e = electronic charge)