List of top Physics Questions

In a series $LR$ circuit with $X _{ L }= R$, power factor is $P _1$ If a capacitor of capacitance $C$ with $X _{ C }= X _{ L }$ is added to the circuit the power factor becomes $P_2$ The ratio of $P_1$ to $P_2$ will be :

The variation of impedance (Z) with angular frequency (w) for two electrical elements is shown in the graph given. If XL,Xc, and R are inductive reactance, capacitive reactance and resistance respectively, then

To increase the resonant frequency in seriesLCR circuit,

Two identical current carrying coils with same centre are placed with their planes perpendicular to each other. If i = $\sqrt{2}A$ and radius of coil R = 1 m, then magnetic field at centre C is equal to:

A dipole having dipole moment M is placed in two magnetic fields of strength B1 and B2 respectively. The dipole oscillates 60 times in 20 seconds in the $B_1$ magnetic field and 60 oscillations in 30 seconds in the $B_2$ magnetic field. Then find the $\frac{B_1}{B_2}$

The characteristics of two coil is given below. If the magnetic moment of both coil A and B are equal then choose the correct relation,

Coil A	Coil B
Radius r_A=10 cm	r_B=20 cm
Number of turns N_A	N_B
Current I_A	I_B

A projectile is fired from horizontal ground with speed $v$ and projection angle $\theta$ When the acceleration due to gravity is $g$, the range of the projectile is $d$ If at the highest point in its trajectory, the projectile enters a different region where the effective acceleration due to gravity is $g^{\prime}=\frac{g}{081}$, then the new range is $d^{\prime}=n d$ The value of $n$ is ___

The following circuit contains diodes with forward bias having resistance $25Ω$, and reverse bias having infinite resistance. The ratio of $\frac{I_{1}}{I_{2}}$ is equal to

If the length of a conductor is increased by 20% and cross-sectional area is decreased by 4% , then calculate the percentage change in the resistance of the conductor.

In a screw gauge, there are 100 divisions on the circular scale and the main scale moves by $05 \,mm$ on a complete rotation of the circular scale The zero of circular scale lies $6$ divisions below the line of graduation when two studs are brought in contact with each other When a wire is placed between the studs, $4$ linear scale divisions are clearly visible while $46^{\text {th }}$ division the circular scale coincide with the reference line. The diameter of the wire is _____$\times 10^{-2} mm$

When two monochromatic light of frequency ν and $\frac{ν}{2}$ are incident on a photoelectric metal, their stopping potential becomes $\frac{V_s}{2}$ and V_s respectively. The threshold frequency for this metal is:

In figure $(A)$, mass ' $2\, m$ ' is fixed on mass ' $m$ ' which is attached to two springs of spring constant $k$ In figure $(B)$, mass ' $m$ ' is attached to two spring of spring constant ' $k$ ' and ' $2\, k$ ' If mass ' $m$ ' in $(A)$ and $(B)$ are displaced by distance ' $x$ ' horizontally and then released, then time period $T_1$ and $T_2$ corresponding to (A) and (B) respectively follow the relation

If the height of the tower used for LOS communication is increased by 21%, the percentage change in range is?

What is the r.m.s value of an alternating current which when passed through a resistor produces heat, which is four times that produced by a current of 2A in the same resistor?

If half life for a radioactive decay reaction is T. Find the time after which $\frac{7}{8}th$ of initial mass decays

The height of liquid column raised in a capillary tube of certain radius when dipped in liquid A vertically is, $5 cm$ If the tube is dipped in a similar manner in another liquid $B$ of surface tension and density double the values of liquid $A$, the height of liquid column raised in liquid $B$ would be ______$m$

The pressure $( P )$ and temperature $( T )$ relationship of an ideal gas obeys the equation $PT ^2=$ constant The volume expansion coefficient of the gas will be :

The output waveform of the given logical circuit for the following inputs $A$ and $B$ as shown below, is :

A source of sound is moving away from a stationary observer with constant velocity 40 m/s. Find frequency heard by observer, if original frequency of source is 400 Hz and speed of sound in air is 360 m/s

In AM modulation, a signal is modulated on a carrier wave such that maximum and minimum amplitude are found to be $6 V$ and $2 V$ respectively The modulation index is

Two projectiles A and B are projected from the same point on ground with same speed of projection as shown. Find the ratio of maximum height attained by A to that of B.

A car travelling at a speed of 30 km/h is brought to halt in 8m by applying brakes. If the same car is traveling at 60 km/h, in how many meters can it be brought to halt with the same braking? (Provide answer in m)

If light is passing through a medium of critical angle 45°, then the wave speed will be

Consider the two different situations X and Y of two concentric coils of N₁ and N₂ turns and radii R₁ and R₂ respectively as shown above. If the magnetic field at O in situation X is B_x and in situation Y is B_y then B_x−B_y is

If at depth ‘$d$’ the gravitational force acting on a particle is 300 N, then what is the force on a particle at depth ‘$\frac d2$’ ?