Physics

Q. What is the dimensions of $\frac{A}{B}$ in the relation $F=A\sqrt{x}+B{t}^2$, where $F$ is the force, $x$ is the distance and $t$ is the time?

1. $\left[M{L}^{-1/2}{T}^2\right]$
2. $\left[L^{-1/2}{T}^2\right]$
3. $\left[M^2{L}^{-1/2}{T}^2\right]$
4. $\left[L^{-1/2}T\right]$

Q.

The dimensional formula for thermal conductivity is (here $\mathrm{K}$ denotes the temperature):

1. $ML{T}^{-3}{K}^{-1}$

2. $ML{T}^{-2}{K}^{-2}$

3. $ML{T}^{-2}K$

4. $ML{T}^{-3}K$

Q.

Write the relation between coefficient of volume expansion and coefficient of linear expansion.

Q.

A car travels along a straight line for first half time with speed $40km/hr$ and the second half time with speed $60km/hr$. Find the average speed of car.

Q.

What are good conductors of heat?

Q. The dimension of coefficient of thermal conductivity is
$(\frac{dQ}{dt}=-KA\frac{dT}{dx})$, where $dQ$ is heat transferred, $dt$ is time taken, $K$ is coefficient of thermal conductivity, $A$ is cross-sectional area of conductor, $dT$ is change in temperature and $dx$ is length of conductor.

1. $\left[M{L}^2{T}^{-2}{K}^{-1}\right]$
2. $\left[ML{T}^{-3}{K}^{-1}\right]$
3. $\left[ML{T}^{-2}{K}^{-1}\right]$
4. $\left[ML{T}^{-3}K\right]$

Q.

State and explain Kirchhoffs Law.

Q.

The potential energy of a particle varies with distance $x$ from a fixed origin as $U=\frac{\left(A\sqrt{x}\right)}{(x^2+B)}$, where $A$and $B$ are the dimensional constants, then find the dimensional formula for $AB$.

Q. de-Broglie wavelength of a body of mass m and kinetic energy E is given by

1. $\lambda =\frac{h}{mE}$
2. $\lambda =\frac{\sqrt{2mE}}{h}$
3. $\lambda =\frac{h}{2mE}$
4. $\lambda =\frac{h}{\sqrt{2mE}}$

Q. Dimentional formula of permeability of free space ${\mu }_0$ is given by

1. $\left[M^{0}L{T}^{-2}{A}^{-2}\right]$
2. $\left[M{L}^2{T}^{-1}{A}^{-2}\right]$
3. $\left[ML{T}^{-2}{A}^{-2}\right]$
4. $\left[M^{0}L{T}^{-1}{A}^{-1}\right]$

Q.

A body is moving with a velocity of $10m/s$. If the motion is uniform, what will be the velocity after 10 seconds?

Q.

The area of the region bounded by curves $y=x\log x$ and $y=2x-2x^2$ is

1. $\frac{1}{2}$ sq units

2. $\frac{3}{12}$ sq units

3. $\frac{7}{12}$sq units

4. None of these

Q. A ball is thrown vertically downward with a velocity of $20\text{m/s}$ from the top of a tower. It hits the ground after some time with a velocity of $80\text{m/s}$. The height of the tower is :
$(g=10{\text{m/s}}^2)$

1. $320\text{m}$
2. $300\text{m}$
3. $360\text{m}$
4. $340\text{m}$

Q. Two metallic spheres of radii $1\text{cm}$ and $3\text{cm}$ are given charges of $-1\times {10}^{-2}\text{C}$ and $5\times {10}^{-2}\text{C}$ respectively. If these are connected by a conducting wire (potential on them becomes equal), the final charge on bigger sphere is

1. $2\times {10}^{-2}\text{C}$
2. $3\times {10}^{-2}\text{C}$
3. $4\times {10}^{-2}\text{C}$
4. $1\times {10}^{-2}\text{C}$

Q. An electric dipole consisting of two opposite charges of $2\times {10}^{-6}C$ each, separated by a distance of 3 cm is placed in an electric field of $2\times {10}^{5}N/C$. The maximum torque on the dipole will be

1. $12\times {10}^{-1}Nm$
2. $12\times {10}^{-3}Nm$
3. $24\times {10}^{-1}Nm$
4. $24\times {10}^{-3}Nm$

Q.

How is an ammeter connected in a circuit how is a voltmeter connected in a circuit?

Q.

What are the three basic components of Communication?

Q.

The inverse of $y=5^{\log \left(x\right)}$ is

1. $x=5^{\log \left(y\right)}$

2. $x=5^{\log \left(y\right)}c$

3. $x=y^{\frac{1}{\log \left(5\right)}}$

4. $x=5^{\frac{1}{\log \left(y\right)}}$

Q.

What is $\frac{dy}{dx}$?

Q.

Prove that $F=ma.$

Q.

Why a ray of light passing through the center of curvature of concave minor gets reflected along the same path?

Q. Find the net force on charge q.

1. $\sqrt{2}\frac{k{q}^2}{a^2}$
2. $\sqrt{3}\frac{k{q}^2}{a^2}$
3. $\sqrt{5}\frac{k{q}^2}{a^2}$
4. $\frac{k{q}^2}{a^2}$

Q. Water droplets are coming from an open tap at a particular rate. The spacing between a droplet observed at $4^{\text{th}}\text{second}$ after its fall, to the next droplet, is $34.3\text{m}.$ At what rate the droplets are coming from the tap ? (Take $g=9.8{\text{m/s}}^2$)

Q.

How do you know if a transistor is NPN or PNP?

Q. The sum of the numbers $436.32,227.2$ and $0.301$ in appropriate significant figures is

1. $663.821$
2. $664$
3. $663.8$
4. $663.82$

Q.

Calculate the value of mean free path $\left(\lambda \right)$ for oxygen molecules at temperature $27°C$ and pressure $1.01\times {10}^{5}Pa$. Assume the molecular diameter $0.3nm$ and the gas is ideal. $\left(1.38\times {10}^{-23}j{K}^{-1}\right)$.

1. $102nm$

2. $32nm$

3. $58nm$

4. $86nm$

Q. Value of $sin37°.cos53°$ is

1. 9/25
2. 12/25
3. 16/25
4. 3/5

Q.

What is thermal conductivity connected in parallel and series?

Q. A body travels the first half of the total distance with velocity $v_1$ and the second half with velocity $v_2$. Calculate the average velocity.

1. $\frac{v_1+v_2}{2}$
2. $\sqrt{v_1{v}_2}$
3. $\sqrt{2v_1{v}_2}$
4. $\frac{2v_1{v}_2}{v_1+v_2}$

Q.

Why electric field is perpendicular to the equipotential surface?