List of top Physics Questions asked in JEE Main

A sinusoidal wave y(t) = 40sin(10 × 106 πt) is amplitude modulated by another sinusoidal wave x(t) = 20sin(1000πt). The amplitude of minimum frequency component of modulated signal is:
The space inside a straight current carrying solenoid is filled with a magnetic material having magnetic susceptibility equal to \(1.2 \times 10^{–5}\). What is fractional increase in the magnetic field inside solenoid with respect to air as medium inside the solenoid?
Two parallel, long wires are kept 0.20 m apart in vacuum, each carrying current of x A in the same direction. If the force of attraction per meter of each wire is \(2 \times 10^{–6} \text{N}\), then the value of x is approximately:
A body of mass M at rest explodes into three pieces, in the ratio of masses 1 : 1 : 2. Two smaller pieces fly off perpendicular to each other with velocities of 30 ms–1 and 40 ms–1 respectively. The velocity of the third piece will be
The activity of a radioactive material is 2.56 × 10–3 Ci. If the half life of the material is 5 days, after how many days the activity will become 2 × 10–5 Ci?
A coil is placed in a time varying magnetic field. If the number of turns in the coil were to be halved and the radius of wire doubled, the electrical power dissipated due to the current induced in the coil would be: (Assume the coil to be short circuited.)
Which of the following physical quantities have the same dimensions?
A cylinder of fixed capacity of 44.8 litres contains helium gas at standard temperature and pressure. The amount of heat needed to raise the temperature of gas in the cylinder by 20.0°C will be (Given gas constant R = 8.3 JK–1-mol–1)
A wire of length L is hanging from a fixed support. The length changes to L1 and L2 when masses 1 kg and 2 kg are suspended, respectively, from its free end. Then the value of L is equal to
Let K1 and K2 be the maximum kinetic energies of photo-electrons emitted when two monochromatic beams of wavelength λ1 and λ2, respectively are incident on a metallic surface. If λ1 = 3λ2 then:
A person moved from A to B on a circular path as shown in figure. If the distance travelled by him is 60 m, then the magnitude of displacement would be
(Given cos135°= –0.7)
Following statements related to radioactivity are given below:
(A) Radioactivity is a random and spontaneous process and is dependent on physical and chemical conditions.
(B) The number of un-decayed nuclei in the radioactive sample decays exponentially with time.
(C) Slope of the graph of loge (no. of undecayed nuclei) Vs. time represents the reciprocal of mean life time (τ).
(D) Product of decay constant (λ) and half-life time (T1/2) is not constant.
Choose the most appropriate answer from the options given below:

In the given circuit the input voltage Vin is shown in figure. The cut-in voltage of p–n junction diode
(D1 or D2) is 0.6 V. Which of the following output voltage (V0) waveform across the diode is correct?

A charge particle moves along circular path in a uniform magnetic field in a cyclotron. The kinetic energy of the charge particle increases to 4 times its initial value. What will be the ratio of new radius to the original radius of circular path of the charge particle
A body of mass 0.5 kg travels on straight line path with velocity v = (3x2 + 4) m/s. The network done by the force during its displacement from x = 0 to x = 2 m is
A certain amount of gas of volume V at 27°C temperature and pressure 2 × 107 Nm–2 expands isothermally until its volume gets doubled. Later it expands adiabatically until its volume gets redoubled. The final pressure of the gas will be (Use, γ = 1.5)
A student in the laboratory measures thickness of a wire using screw gauge. The readings are 1.22 mm, 1.23 mm, 1.19 mm and 1.20 mm. The percentage error is \(\frac{x}{121}\)%. The value of x is _________.

A block of metal weighing 2 kg is resting on a frictionless plane (as shown in figure). It is struck by a jet releasing water at a rate of 1 kgs–1 and at a speed of 10 ms–1. Then, the initial acceleration of the block, in ms–2, will be:

A block of metal weighing 2 kg is resting on a frictionless plane

Following statements are given:
(A) The average kinetic energy of a gas molecule decreases when the temperature is reduced.
(B) The average kinetic energy of a gas molecule increases with increase in pressure at constant temperature.
(C) The average kinetic energy of a gas molecule decreases with increase in volume.
(D) Pressure of a gas increases with increase in temperature at constant pressure.
(E) The volume of gas decreases with increase in temperature.
Choose the correct answer from the options given below:

In van der Wall equation

\([P=\frac{a}{V^2}[v-b]=RT;\)

P is pressure, V is volume, R is universal gas constant and T is temperature. The ratio of constants a/b is dimensionally equal to:

Two vectors \(\overrightarrow{A}+\overrightarrow{B}\) have equal magnitudes. If magnitude of \(\overrightarrow{A}+\overrightarrow{B}\) is equal to two times the magnitude of \(\overrightarrow{A}-\overrightarrow{B}\) then the angle between vec A and \(\overrightarrow{B}\) will be

A zener of breakdown voltage VZ = 8 V and maximum Zener current, IZM = 10 mA is subjected to an input voltage Vi = 10 V with series resistance R = 100 Ω. In the given circuit RL represents the variable load resistance. The ratio of maximum and minimum value of RL is __________.
The escape velocity of a body on a planet ‘A’ is 12 kms–1. The escape velocity of the body on another planet ‘B’, whose density is four times and radius is half of the planet ‘A’, is
At a certain place the angle of dip is 30° and the horizontal component of earth’s magnetic field is 0.5 G. The earth’s total magnetic field (in G), at that certain place, is
A longitudinal wave is represented by \(x=10 \,sin⁡\,2π (nt−\frac{x}{λ})cm\). The maximum particle velocity will be four times the wave velocity if the determined value of wavelength is equal to