List of top Physics Questions

In a transistor circuit, if emitter and collector connections are interchanged then
A body is thrown vertically upwards with an initial velocity \( u \). If \( g \) is the acceleration due to gravity, then the total time taken for the body to return to the starting point is:
The following is not used as a nuclear fuel.
A radioactive material whose half life period is 2 years weighs 1 g and is stored in the laboratory for 4 years. Then the amount of remaining radioactive material is
To heat the food containing water, the frequency of the microwaves used in microwave oven is:
The self-inductance of a long solenoid of cross-sectional area \( A \), length \( l \) and \( n \) turns per unit length is given by:
The threshold wavelength of a photosensitive material is equal to the frequency of H$_\alpha$ line of hydrogen. If a photon whose frequency equal to the frequency of H$_\beta$ line of hydrogen is incident on this photosensitive material, the maximum kinetic energy of the emitted photoelectrons is: (R -- Rydberg's constant, h -- Planck's constant and c -- speed of light in vacuum)
A resistor of resistance 40 \( \Omega \), a capacitor of capacitive reactance 20 \( \Omega \) and an inductor of inductive reactance 50 \( \Omega \) are connected in series to an ac source of 100 V. The current through the circuit is:
In a hydrogen atom, an electron in an orbit with principal quantum number \( n \) jumps to the first excited state, emitting a photon of wavelength \( \lambda \). Then the value of \( n \) is:
Eight drops of mercury, each of the same radius and same charge, combine to form a bigger drop. The ratio of the capacitance of the bigger drop to that of each smaller drop is:
Which of the following do not exist?
The given circuit shows two capacitors connected to a battery. After the capacitors are completely charged, the battery is removed and the capacitors are connected with plates of opposite polarity together. Then the energy lost in the process is:
two capacitors connected to a battery
A straight wire carrying a current of 12 A is bent into a semi-circular arc of radius 2 cm as shown in the figure. Then the magnetic field due to the straight segments at the centre of the arc is
A straight wire carrying a current of 12 A
A cyclotron’s oscillator frequency is 20 MHz. The operating magnetic field for accelerating protons is
(Charge of proton = \( 1.6 \times 10^{-19} \) C, mass of proton = \( 1.67 \times 10^{-27} \) kg)
Two cells with same emf E but different internal resistances, $r_1$ and $r_2$ are connected in series to an external resistance R. If the potential difference across the first cell is zero then the value of R is
Choose the correct option with respect to the statements A and B.
A diatomic gas has an initial internal energy of 80 cal. A work of 18 cal is done on the gas, and the gas releases heat energy of 42 J. The final internal energy of the gas is:
Three moles of a gas at a temperature \( T \) are heated to thrice its volume by keeping the pressure constant. If \( \gamma \) is the ratio of specific heats, then the increase in internal energy of the gas is:
The energy (in eV) possessed by a neon atom at $77^\circ$C is (Boltzmann constant, $k_B = 1.38 \times 10^{-23}$ J K$^{-1}$)
Among the following, the charge that does not exist on any type of charged body is:
The vector form of the universal law of gravitation:
A 50 g ice cube at -10°C is added to 200 g of water at 30°C. The final temperature of the mixture is: (Specific heat of water = 1 cal g\(^{-1}\)°C\(^{-1}\), latent heat of fusion of ice = 80 cal g\(^{-1}\), specific heat of ice = 0.5 cal g\(^{-1}\)°C\(^{-1}\))
The relation between volume (V) and absolute temperature (T) of a gas in an adiabatic process is:
The pressure required to decrease the volume of 4000 cc of water by 0.05%: (Bulk modulus of water = \( 2.2 \times 10^9 \, \text{Nm}^{-2} \))
A block of mass \( M \) hangs from a spring and oscillates vertically with an angular frequency \( \omega \). If the block is removed from the spring, when it is in equilibrium position, the spring shortens by: