List of top Physics Questions

A plate has a length $ 5\pm 0.1\text{ }cm $ and breadth $ 2\pm 0.01\text{ }cm $ . Then the area of the plate is:

Two vectors are given by $\vec{A}=\left(3\hat{i} +\hat{j}+3\hat{k}\right)$ and $ \vec{B}=\left(3\hat{i} +5\hat{j}-2\hat{k}\right)$. Find the third vector $\vec{C}$ if $\vec{A}+3\vec{B}-\vec{C}=0.$

The current gain a of a transistor is $0.9.$ The transistor is connected to common base configuration. What would be the change in collector current when base current changes by $ 4\,mA $ ?

Two projectiles are fired at different angles with the same magnitude of velocity, such that they have the same range. At what angles they might have been projected?

In a full wave rectifier circuit operating from $ 50\,Hz $ main frequency, the fundamental frequency in the ripple would be

Consider the following statements A and B. Identify the correct answers. A. A zener diode is always connected in reverse bias. B. The potential barrier of a p-n junction lies between 0.1 to 0.3 V, approximately.

2 kg of ice at -20$^{\circ}$C is mixed with 5 kg of water at 20$^{\circ}$C in an insulating vessel having a negligible heat capacity. Calculate the final mass of water remaining in the container. It is given that the specific heats of water and ice are 1 kcal/kg / $^{\circ}$C and 0.5 kcal/kg /$^{\circ}$C while the latent heat of fusion of ice is 80 kcal/kg

A sample of radioactive element has a mass of $10\, g$ at an instant $t = 0.$ The approximate mass of this element in the sample after two mean lives is

A particle moves along the $x$-axis from $x=x_{1}$ to $x=x_{2}$ under the action of a force given by $F=2 x$. Then the work done in the process is

According to Curie's law, the magnetic susceptibility of a substance at an absolute temperature $T$ is proportional to

$A n-p-n$ transistor conducts when

A particle moves along a circle of radius $\left(\frac{20}{\pi}\right) m$ with constant tangential acceleration. If the velocity of the particle is $80\, m/s$ at the end of the second revolution after motion has begun, the tangential acceleration is

A diamagnetic material in a magnetic field moves

Fuse wire is a wire of

An ideal gas heat engine operates in a Carnot cycle between $227^{\circ} C $ and $127^{\circ} C. $ It absorbs $6\, kcal$ at the higher temperature. The amount of heat (in kcal) converted into work is equal to

How many $\alpha$-particle and $\beta$-particles are emitted when uranium nucleus ${ }_{92}^{238} U$ decays to lead nucleus ${ }_{82}^{206} P b$ ?

A cord attached to a vibrating tuning fork is divided into six segments under tension of $36 \,N$. It will be divided into fowl segments, if the tension is:

Ohm's law is not obeyed by:

An electric kettle has two heating coils. When one of the coils is connected to an a.c. source, the water in the kettle boils in $10$ minutes. When the other coil is used the water boils in $40$ minutes. If both the coils are connected in parallel, the time taken by the same quantity of water to boil will be

13 resistors each of resistance $R\,\Omega$ are connected in the circuit as shown in figure. The effective resistance between A and B is

When 100 V d.c. is applied across a coil, a current of 1 A flows through it. When 100 V a.c. of 50 Hz is applied to the same coil only 0.5 A flows. The inductance of the coil is

As a result of interference of two coherent sources of light, energy is

A wire in the form of a circular loop of one turn carrying a current produces a magnetic field B at the centre. If the same wire is looped into a coil of two turns and carries the same current, the new value of magnetic induction at the centre is

If both the mass and radius of the earth decrease by $1%$. then