List of top Physics Questions asked in JEE Main

The disintegration rate of a certain radioactive sample at any instant is 4250 disintegrations per minute. 10 minutes later, the rate becomes 2250 disintegrations per minute. The approximate decay constant is
(Take log101.88 = 0.274)

A bullet is shot vertically downwards with an initial velocity of 100 m/s from a certain height. Within 10s, the bullet reaches the ground and instantaneously comes to rest due to the perfectly inelastic collision. The velocity-time curve for total time t = – 20s will be 

(Take g = 10 m/s2)

The total charge on the system of capacitors C1 = 1 μF, C2 = 2 μF, C3 = 4 μF and C4 = 3 μF, connected in parallel is :
(Assume a battery of 20 V is connected to the combination)
Light travels in two media \(M_1\) and \(M_2\) with speeds \(1.5 × 10^8ms^{–1 }\)and \(2.0 × 10^8ms^{–1}\), respectively. The critical angle between them is:
In a series \(LR\) circuit \(X_L=R\) and power factor of the circuit is \(P_1\). When capacitor with capacitance C such that \(X_L=X_C\) is put in series, the power factor becomes \(P_2\). The ratio \(\frac {P_1}{P_2}\) is
A nucleus of mass M at rest splits into two parts having masses \(\frac{M′}{3}\) and \(\frac{2M′}{3}(M′<M).\)
A body is projected vertically upwards from the surface of earth with a velocity equal to one third of escape velocity. The maximum height attained by the body will be:
A transverse wave is represented by \(y = 2sin(ωt – kx)\) \(cm\). The value of wavelength (in cm) for which the wave velocity becomes equal to the maximum particle velocity, will be

Choose the correct answer.

1. A torque meter is calibrated to reference standards of mass, length and time each with 5% accuracy. After calibration, the measured torque with this torque meter will have net accuracy of

A radio can tune to any station in 6 MHz to 10 MHz band. The value of corresponding wavelength bandwidth will be
A gas has n degrees of freedom. The ratio of specific heat of gas at constant volume to the specific heat of gas at constant pressure will be
BX and BY are the magnetic field at the centre of two coils X and Y, respectively each carrying equal current. If coil X has 200 turns and 20 cm radius and coil Y has 400 turns and 20 cm radius, the ratio of BX and BY is
When a particle executes Simple Harmonic Motion, the nature of graph of velocity as a function of displacement will be :
The current I in the given circuit will be
The current I in the given circuit
A battery of 6V is connected to the circuit as shown below. The current I drawn from the battery is

A battery of 6 V is connected to the circuit
7 mol of a certain monoatomic ideal gas undergoes a temperature increase of 40 K at constant pressure. The increase in the internal energy of the gas in this process is:
(Given R = 8.3 JK–1 mol–1)
Sand is being dropped from a stationary dropper at a rate of 0.5 kgs–1 on a conveyor belt moving with a velocity of 5 ms–l. The power needed to keep the belt moving with the same velocity will be
Given below are two statements
Statement-I: A point charge is brought in an electric field. The value of electric field at a point near to the charge may increase if the charge is positive.
Statement-II: An electric dipole is placed in a non-uniform electric field. The net electric force on the dipole will not be zero.
Choose the correct answer from the options given below.
The aperture of the objective is 24.4 cm. The resolving power of this telescope, if a light of wavelength 2440 Å is used to see the object will be:

Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : Product of Pressure (P) and time (t) has the same dimension as that of coefficient of viscosity.
Reason R : Coefficient of viscosity
\(= \frac{Force}{Velocity ∼ gradient}\)

Choose the correct answer from the options given below.

In an experiment of determine the Young’s modulus of wire of a length exactly 1 m, the extension in the length of the wire is measured as 0.4 mm with an uncertainty of ±0.02 mm when a load of 1 kg is applied. The diameter of the wire is measured as 0.4 mm with an uncertainty of ±0.02 mm when a load of 1 kg is applied. The diameter of the wire is measured as 0.4 mm with an uncertainty of ± 0.01 mm. The error in the measurement of Young’s modulus (ΔY) is found to be x × 1010 Nm–2. The value of x is ___.
(Take g=10 m/s2)
The velocity of sound in a gas, in which two wavelengths, 4.08 m and 4.16 m produce 40 beats in 12 s, will be:

The three charges q/2, q and q/2 are placed at the corners A, B and C of a square of side ‘a’ as shown in figure. The magnitude of electric field (E) at the corner D of the square is
 

Fig.

Motion of a particle in x–y plane is described by a set of following
\(x = 4sin (\frac{π}{2} - ωt )m\)
and y = 4sin(ωt) m. The path of the particle will be

In the following circuit, the correct relation between output (Y) and inputs A and B will be:
 

Fig. Circuit