List of practice Questions

The velocity of the electron in Bohr’s first orbit is \( x \times 10^6 \, \text{ms}^{-1} \). The deBroglie wavelength associated with it (in nm) is (Given: \( m_e = 9 \times 10^{-31} \, \text{kg}, \, h = 6.6 \times 10^{-34} \, \text{Js} \))
A light from Paschen series of hydrogen atom is able to eject photoelectrons from a metal. Then the work function of the metal is
A light from Paschen series of hydrogen atom is able to eject photoelectrons from a metal. Then the work function of the metal is
A light from Paschen series of hydrogen atom is able to eject photoelectrons from a metal. Then the work function of the metal is
The average number of photons emitted per second by a laser of power \(6.6 \times 10^{-3}\) W producing a light of wavelength 600 nm is (Planck’s constant, \(h = 6.6 \times 10^{-34}\) J·s)
The average number of photons emitted per second by a laser of power \(6.6 \times 10^{-3}\) W producing a light of wavelength 600 nm is (Planck’s constant, \(h = 6.6 \times 10^{-34}\) J·s)
The average number of photons emitted per second by a laser of power \(6.6 \times 10^{-3}\) W producing a light of wavelength 600 nm is (Planck’s constant, \(h = 6.6 \times 10^{-34}\) J·s)
The correct statement of the following is
A 100 \(\mu F\) capacitor is connected to a 100 V, 50 Hz AC supply. The rms value of the current is
A bulb of power 660 W radiates uniformly in all directions. The pressure exerted by the radiation on the surface at a distance of 5 m is
A long solenoid having 100 turns per cm carries a current of \(\frac{4}{\pi}\) A. At the centre of it is placed a coil of 200 turns of cross sectional area 25 cm\(^2\) having its axis parallel to the field produced by the solenoid. When the direction of the current in the solenoid is reversed within 0.04 s, the induced emf in the coil is
A particle of charge \(1.0 \times 10^{-16}\) C moves through a uniform magnetic field \(\vec{B} = B_0 (\hat{i} + 4\hat{j})\) T. The particle velocity at some instant is \(\vec{V} = (2\hat{i} + 4\hat{j})\) m/s and the magnetic force acting on it is \(3 \times 10^{-16}\) N. The magnitude of \(B_0\) is
A short bar magnet produces a magnetic field of \(6.4 \times 10^{-5}\) T at a distance of 20 cm from the center of the magnet on the normal bisector of the magnet. The magnetic field produced by this magnet at a distance of 40 cm on the axis is
A solenoid has the length 1 m and the area of cross section \(0.02\ \text{m}^2\). If no. of turns in the solenoid is 5000 then the self inductance of the solenoid is
The equation that represents magnetic field of a plane electromagnetic wave which is propagating along x-direction with wavelength 10 mm and maximum electric field 60 V m$^{-1}$ in y-direction is (c – speed of light)
A beam of light is incident from air on the surface of a liquid. The angle of incidence is $\theta$ and the angle of refraction is $\alpha$. If the critical angle for liquid when surrounded by air is $\theta_{c}$ then $\sin\theta_{c}$ is
A capacitor has capacitance \(C_0\) when there is no dielectric between its plates. Two slabs of dielectric constant \(K_1\), \(K_2\) respectively with area equal to area of plates but thickness half of the distance between the plates are placed in between the plates. Then the new capacitance is
In a parallel plate capacitor, if \(10^{12}\) electrons pass from one plate to another, a potential difference of 10 V is developed across the plates. The capacitance of the capacitor is
In Young's double slit experiment, light of wavelength 480 nm is incident on two slits separated by a distance of \(4 \times 10^{-7}\) m. If a thin plate of thickness \(1.4 \times 10^{-6}\) m and refractive index \(\frac{13}{7}\) is placed between one of the slits and screen, the phase difference introduced at the position of central maxima is
The current \(i\) in the circuit given below is
current i in the circuit given below is
Three charges +5q, Q and -2q are kept along a straight line in the same order such that, +5q and -2q charges are at a distance of \(\frac{2r}{3}\) and \(\frac{r}{3}\) from the charge Q respectively. If the net force on the charge -2q is zero, then Q is
Two wires A and B of same material having length \(L_A, L_B\) and radii \(R_A, R_B\) and drift velocity \(V_A, V_B\) respectively carries same current. If \(L_A = L_B\) and \(R_A = 2 R_B\) then the value of \(\frac{V_A}{V_B}\) is
A gaseous mixture consists of 4 g of oxygen and 4 g of helium. The ratio \( \frac{C_p}{C_v} \) of the mixture is
A large tank open to the atmosphere at the top and filled with water develops a small hole in the side at a point 20 m below the water level. If the rate of flow of water from the hole is \(3 \times 10^{-3}\,\text{m}^3/\text{min}\), then the area of the hole is: (Take \( g = 10\,\text{m/s}^2 \))
One mole of an ideal monatomic gas undergoes the process A $\rightarrow$ B $\rightarrow$ C $\rightarrow$ D $\rightarrow$ A as shown in the graph. The work done during the process is
an ideal monatomic gas undergoes the process A → B → C → D →A