List of top Physics Questions

A Zener diode of breakdown voltage 20 V is connected as shown in the given circuit. The current through Zener diode is
A Zener diode of breakdown voltage 20 V
A wire of resistance 100 \(\Omega\) is stretched so that its length increases by 20%. The stretched wire is then bent in the form of a rectangle whose length and breadth are in the ratio 3 : 2. The effective resistance between the ends of any diagonal of the rectangle is
The magnetic field at a distance of 10 cm from a long straight thin wire carrying a current of 4 A is
A capacitor of capacitance 2\(\mu\)F is charged to 50 V and then disconnected from the source. Later the gap between the plates of the capacitor is filled with a dielectric material. If the energy stored in the capacitor is decreased by 25% of its initial value, then the dielectric constant of the dielectric material is
A closely wound solenoid of 1200 turns and area of cross-section 5 cm\(^2\) carries a current. If the magnetic moment of the solenoid is 1.2 J T\(^{-1}\), then the current through the solenoid is
Two sound waves of wavelengths 99 cm and 100 cm produce 10 beats in a time of \( t \) seconds. If the speed of sound in air is 330 m/s, then the value of \( t \) in seconds is
From the figure shown for a thermodynamic system, match the curves with their respective thermodynamic processes (P - Pressure and V - Volume)
thermodynamic system,
Curve | Process I | a) Adiabatic
II | b) Isobaric
III | c) Isochoric
IV | d) Isothermal
If a refrigerator of coefficient of performance (COP) 5 has a freezer at a temperature of -13 °C, then the room temperature is
According to Zeroth Law of Thermodynamics, the physical quantity which is same for two bodies in thermal equilibrium is
As shown in the figure, a light uniform rod PQ of length 150 cm is suspended from the ceiling horizontally using two metal wires A and B tied to the ends of the rod. The ratios of the radii and the Young’s modulus of the materials of the two wires A and B are respectively 2 : 3 and 3 : 2. The position at which a weight should be suspended from the rod such that the elongations of the two wires become equal is
light uniform rod PQ of length 150 cm is suspended
The angular frequency of a block of mass 0.1 kg oscillating with the help of a spring of force constant 2.5 N m\(^{-1}\) is:
If water flows with a velocity of 20 cm/s in a pipe of radius 2 cm, then the flow is (The coefficient of viscosity of water is \(10^{-3} \, \mathrm{kg\,m^{-1}s^{-1}}\) and density of water is \(10^{3} \, \mathrm{kg\,m^{-3}}\))
An electric kettle takes 4 A current at 220 V. If the entire electric energy is converted into heat energy, then the time (in minutes) taken to increase the temperature of 1 kg of water from 34 °C to 100 °C is
If the radius of gyration of a thin circular ring about an axis passing through its centre and perpendicular to its plane is $10\sqrt{2}$ cm, then its radius about its diameter is
Identify the correct option from the following:
A person holds a ball of mass 0.25 kg in his hand and throws it, so that it leaves his hand with a speed of 12 m s$^{-1}$. In the process, if his hand moved through a distance of 0.9 m, then the net force acted on the ball is
Identify the correct option from the following:
If bullets are fired in all possible directions from same point with equal velocity of 10 m s$^{-1}$ and an angle of projection 45$^\circ$, then the area covered by the bullets on the ground nearby (acceleration due to gravity 10 m s$^{-2}$) is
Identify the correct option from the following:
If a car travels 40% of the total distance with a speed $v_1$, then the remaining distance with the car is
Identify the correct option from the following:
The heights of the transmitting and receiving antennas are respectively $\frac{1}{2000}$ and $\frac{1}{5000}$ times the radius of the Earth. The maximum distance between these two antennas for satisfactory communication in line of sight is}
(Radius of the Earth = 6.4 $\times 10^6$ m)
If the half-life of a radioactive material is 10 years, then the percentage of the material decayed in 30 years is
The minimum wavelength of X-rays produced by 20 keV electrons is nearly
In a solenoid, if the current of 15 A passes through the solenoid of length 25 cm, radius 2 cm, and number of turns 500, then the magnetic moment of the solenoid is
Two moving coil galvanometers A and B having identical springs are placed in magnetic fields of 0.25 T and 0.5 T respectively. If the number of turns in A and B are 36 and 48, the areas of the coils A and B are 2.4 $\times 10^{-3}$ m$^2$ and 4.8 $\times 10^{-3}$ m$^2$ respectively, then the ratio of the current sensitivities of the galvanometers A and B is
When photons of energy 8 $\times 10^{-19}$ J incident on a photosensitive material, the work function of the photosensitive material is nearly 10 eV, then the maximum kinetic energy of the photoelectrons emitted is
(1) 3.5 eV
(2) 2.5 eV
(3) 2.0 eV
(4) 1.0 eV
If a dielectric slab of dielectric constant 3 is introduced between the plates of a capacitor having electric field $1.5\, N/C$, then the electric displacement is
An electric charge $10^{-3}\, \mu C$ is placed at the origin of the x-y plane. The potential difference between points A and B located at $(\sqrt{2}\, m, \sqrt{2}\, m)$ and $(2m, 0m)$ respectively is