PHYSICS 9th JAN S1 2020 - JEE MCQ

A particle moving with kinetic energy E has de Broglie wavelength λ. If energy ΔE is added to its
energy, the wavelength become λ/2. Value of ΔE, is :

the screw on a screw–gauge is given six rotations, it moves by 3mm on the main scale. If there are 50
divisions on the circular scale the least count of the screw gauge is :

A charged particle of mass 'm' and charge 'q' moving under the influence of uniform electric field Ei^{^} and a uniform magnetic field Bk^∧  follows a trajectory from point P to Q as shown in figure. The velocities
at P and Q are respectively vi^{^} and -2vj^{^} Then which of the following statements (A, B, C, D) are the
correct ? (Trajectory shown is schematic and not to scale)

Three harmonic waves having equal frequency v and same intensity I₀, have phase angles 0,π/2 and -π/4 respectively. When they are superimposed the intensity of the resultant wave(in I₀) is close to

Consider a force F^→= -xi^{^}+yj^{^}.The work done by this force in moving a particle from point A(1, 0) to
B(0, 1) along the line segment is :
(All quantities are in SI units)

Three solid spheres each of mass m and diameter d are stuck together such that the lines connecting
the centres form an equilateral triangle of side of length d. The ratio I₀/I_A of moment of inertial I_A of the
system about an axis passing the centroid and about center of any of the spheres I_A and perpendicular
to the plane of the triangle is

A vessel of depth 2h is half filled with a liquid of refractive index  2√2  and the upper half with another
liquid of refractive index √2 . The liquids are immiscible. The apparent depth of the inner surface of the
bottom of vessel will be

A body A of mass m is moving in a circular orbit of radius R about a planet. Another body B of mass m/2 collides with A with a velocity which is half v^→/2 the instantaneous velocity v^→ of A.The collision is
completely inelastic. Then, the combined body

In the given circuit diagram, a wire is joining points B and D. The current(in A) in this wire is

Consider two ideal diatomic gases A and B at some temperature T. Molecules of the gas A are rigid,
and have a mass m. Molecules of the gas B have an additional vibrational mode, and have a mass m/4 The ratio of the specific heats (C_v^A and C_v^B) of gas A and B, respectively is :

Two particles of equal mass m have respective initial velocities u i^{^} and u(i^{^} +j^{^}/2).They collide
completely inelastically. The energy lost in the process is

Which of the following is an equivalent cyclic process corresponding to the thermodynamic cyclic given
in the figure ? where, 1 →2 is adiabatic. (Graphs are schematic and are not to scale)

Water flows in a horizontal tube (see figure). The pressure of water changes by 700 Nm^-2 between A
and B where the area of cross section are 40 cm² and 20 cm², respectively. Find the rate of flow of
water through the tube.
(density of water = 1000 kgm^-3)

A quantity f is given by f =√(hc⁵/G) where c is speed of light, G universal gravitational constant and h is
the Planck's constant. Dimension of f is that of

Consider a sphere of radius R which carries a uniform charge density ρ. If a sphere of radius R/2 is
carved out of it, as shown, the ratio E_A/E_B  of magnitude of electric field E_A and E_B , respectively, at
points A and B due to the remaining portion is :

The distance x covered by a particle in one dimensional motion varies with time t as x² = at² + 2bt + c. If
the acceleration of the particle depends on x as x^-n, where n is an integer, the value of n is …….

Both the diodes used in the circuit shown are assumed to be ideal and have negligible resistance when
these are forward biased. built in potential in each diode is 0.7 V. For the input voltages shown in the
figure, the voltage (in volts) at point A is ………

One end of a straight uniform 1 m long bar is pivoted on horizontal table. It is released from rest when it
makes an angle 30° from the horizontal (see figure). Its angular speed when it hits the table is given as
√n s^-1, where n is an integer. The value of n is …..

A body of mass m = 10 kg is attached to one end of a wire of length 0.3 m. The maximum angular
speed (in rad s^-1) with which it can be rotated about its other end in space station is (Breaking stress of
wire = 4.8 × 10⁷ Nm^-2 and area of cross section of the wire = 10^-2 cm²) is :

In a fluorescent lamp choke (a small transformer) 100 V of reverse voltage is produced when the choke
current changes uniformly from 0.25 A to 0 in a duration of 0.025 ms. The self–inductance of the choke
(in mH) is estimated to be ………