List of top Physics Questions

A mass falls from a height 'h' and its time of fall $'l'$ is recorded in terms of time period T of a simple pendulum. On the surface of earth it is found that I = 2T. The entire set up is taken on the surface of another planet whose mass is half of that of earth and radius the same. Same experiment is repeated and corresponding times noted as t' and T'.
Two objects of mass m each moving with speed u m/s collide at 90°, then final momentum is (assume collision is inelastic)
A rigid square loop of side 'a' and carrying current I$_2$ is lying on a horizontal surface near a long current I$_1$ carrying wire in the same plane as shown in figure. The net force on the loop due to wire will be :
The actual value of resistance $R$, shown in the figure is $30 \Omega $. This is measured in an experiment as shown using the standard formula $R = \frac{V}{I}$ , where $V$ and $I$ are the readings of the voltmeter and ammeter, respectively. If the measured value of $R$ is $5\%$ less, then the internal resistance of the voltmeter is :
A $20$ Henry inductor coil is connected to a $10$ ohm resistance in series as shown in figure. The time at which rate of dissipation of energy (joule's heat) across resistance is equal to the rate at which magnetic energy is stored in the inductor is :
Two plane mirrors arc inclined to each other such that a ray of light incident on the first mirror $(M_1)$ and parallel to the second mirror $(M_2)$ is finally reflected from the second mirror $(M_2)$ parallel to the first mirror $(M_1)$. The angle between the two mirrors will be :
Determine the charge on the capacitor in the following circuit :
Two identical breakers A and B contain equal volumes of two different liquids at $60^{\circ}C$ each and left to cool down. Liquid in A has density of $8 \times 10^2 \; kg/m^3$ and sp ecific heat o f 2000 J $kg^{-1} \; K^{-1}$ while liquid in B has density o f 103 kg m-3 and sp ecific heat o f 4000 J $kg^{-1} K^{-1}$. Which of the following best describes their temperature versus time graph schematically? (assume the emissivity of both the beakers to be the same)
One of the two identical conducting wires of length $L$ is bent in the form of a circular loop and the other one into a circular coil of $N$ identical turns. If the same current is passed in both, the ratio of the magnetic field at the central of the loop $(B_L)$ to that at the centre of the coil $(B_C)$ , i.e., $R \frac{B_L}{B_C}$ will be
In the circuit shown, the switch $S_1$ is closed at time $t = 0$ and the switch $S_2$ is kept open. At some later time $(t_0)$, the switch $S_1$ is opened and $S_2$ is closed. The behavious of the current $I$ as a function of time $'t'$ is given by :
A solid sphere and solid cylinder of identical radii approach an incline with the same linear velocity (see figure). Both roll without slipping all throughout. The two climb maximum heights $h_{sph}$ and $h_{cyl}$ on the incline. The ratio $\frac{h_{sph}}{h_{cyl}}$ is given by :
Maximum kinetic energy gained by the charged particle in the cyclotron is independent of
Which colour of the light has the longest wavelength?
Water flows into a large tank with flat bottom at the rate of $10^{-4} \; m^3 s^{-1}$. Water is also leaking out of a hole of area $1\, cm^2$ at its bottom. If the height of the water in the tank remains steady, then this height is :
A galvanometer, whose resistance is $50\, ohm$, has $25$ divisions in it. When a current of $4 \times 10^{-4}$ A passes through it, its needle (pointer) deflects by one division. To use this galvanometer as a voltmeter of range $2.5\, V$, it should be connected to a resistance of:
A metal ball of mass $0.1\, kg$ is heated upto $500^{\circ}C$ and dropped into a vessel of heat capacity $800 \; JK^{-1}$ and containing $0.5\, kg$ water. The initial temperature of water and vessel is $30^{\circ}C$. What is the approximate percentage increment in the temperature of the water ? [Specific Heat Capacities of water and metal are, respectively, $4200 \; Jkg^{-1} K^{-1}$ and $400 \; JKg^{-1} K^{-1}$]
A body of mass $1\, kg$ falls freely from a height of $100\, m$ on a platform of mass $3\, kg$ which is mounted on a spring having spring constant $k = 1.25 \times 10^6 \; N/m$. The body sticks to the platform and the spring's maximum compression is found to be $x$. Given that $g = 10 \; ms^{-2}$, the value of $x$ will be close to :
Figure shown a $DC$ voltage regulator circuit, with a Zener diode of breakdown voltage = $6V$. If the unregulated input voltage varies between $10\, V$ to $16\, V$, then what is the maximum Zener current ?
For a p-type semiconductor, which of the following statements is true ?
A block of mass $m$, lying on a smooth horizontal surface, is attached to a spring (of negligible mass) of spring constant $k$. The other end of the spring is fixed, as shown in the figure. The block is initally at rest in its equilibrium position. If now the block is pulled with a constant force $F$, the maximum speed of the block is :
Glass has refractive index $\mu$ with respect to air and the critical angle for a ray of light going from glass to air is $\theta$. If a ray of light is incident from air on the glass with angle of incidence $\theta$, corresponding angle of refraction is
The stopping potential of the photoelectrons, from a photo cell is
A molecule of water on the surface experiences a net
A paramagnetic substance in the form of a cube with sides $1\, cm$ has a magnetic dipole moment of $20 \times 10^{-6} \; J/T$ when a magnetic intensity of $60 \times 10^3 \; A/m$ is applied. Its magnetic susceptibility is :
Two putty balls of equal mass moving with equal velocity in mutually perpendicular directions, stick together after collision. If the balls were initially moving with a velocity of $45\sqrt{2}$ m/sec each, the velocity of their combined mass after collision is (in m/sec).