List of top Physics Questions asked in KEAM

A Carnot engine operating between temperatures $T_1$ and $T_2$ has efficiency $0.2$. When $T_2$ is reduced by $50\, K$, its efficiency increases to $0.4$. Then $T_1$ and $T_2$ are respectively

An electron, placed in an electric field, experiences a force F of $1\, N.$ What are the magnitude and direction of the electric field E at the point where the electron is located $(e = 1.6 \times 10^{-19} C)$ ?

A $ 2\mu C $ charge moving around a circle with a frequency of $ 6.25\times {{10}^{12}}Hz $ produces a magnetic field $6.28\, T$ at the centre of the circle. The radius of the circle is

A common emitter amplifier gives an output of $ 3 \,V $ for an input of $ 0.01 \,V $ . If $ \beta $ of the transistor is $100$ and the input resistance is $ 1\text{ }k\Omega , $ then the collector resistance is

A body of mass $60 \,kg$ suspended by means of three strings $P, Q$ and $R$ as shown in the figure is in equilibrium. The tension in the string $P$ is

The area under velocity-time graph for a particle in a given interval of time represents

The direction of propagation of electromagnetic wave is along

A solid cylinder rolls down an inclined plane of height 3 m and reaches the bottom of plane with angular velocity, of 2 $ \sqrt {2} rads ^{-1} $ . The radius of cylinder must be (Take g = 10 $ ms ^{-2}$ )

A wire of natural length $ l, $ Youngs modulus $ Y $ and area of cross-section $ A $ is extended by $ x $ . Then the energy stored in the wire is given by

After terminal velocity is reached, the acceleration of a body falling through a fluid is

A transverse wave is described by the equation $ y={{y}_{0}}\sin 2\pi \left( ft-\frac{x}{\lambda } \right). $ The maximum particle velocity is equal to four times the wave velocity, if

A ray of light passes through an equilateral prism such that an angle of incidence is equal to the angle of emergence and the latter is equal to $ \frac{3}{4} $ th the angle of prism. The angle of deviation is:

A particle of mass $m$ and charge $q$ with an initial velocity $v$ is subjected to a uniform magnetic field $B$ along the vertical direction. The particle will

If the unit of force and length are doubled, the unit of energy will be

A particle of mass m is moving along the x-axis under the potential $V (x) = \frac{kx^2}{2} + \frac{\lambda}{x}$, where $k $ and $\lambda$ are positive constants of appropriate dimensions. The particle is slightly displaced from its equilibrium position. The particle oscillates with the angular frequency $\omega$ given by

A stone falls freely from rest from a height $h$ and it travels a distance $\frac{9h}{25}$ in the last second. The value of $h$ is

Identify the mismatched pair from the following

An electric dipole consists of two opposite charges each 0.05 $\mu$C separated by 30 mm. The dipole is placed in an uniform external electric field of $ 10^6 \, NC^{ - 1}$. The maximum torque exerted by the field on the dipole is

The length of a rubber cord is $ {{l}_{1}} $ metre when the tension is $ 4\, N $ and $ {{l}_{2}} $ metre when the tension is $ 6\, N $ . The length when the tension is $9\,N$, is

For signal transmission, modulation is necessary

Two planets have radii $r_1$ and $r_2$ and densities $d_1$ and $d_2$ respectively. Then the ratio of accelerations due to gravity on them is

A voltage $V_{PQ} = V_0 \, \cos \, \omega t$ (where $V_0$ is a real amplitude) is applied between the points P and Q in the network shown in the figure. The values of capacitance and inductance are $C = \frac{1}{\omega R \sqrt{3}}$ and $L = \frac{R \sqrt{3}}{\omega}$ Then, the total impedance between P and Q is

A pendulum of length 1 m is released from $\theta$ = 60$^{\circ}$. The rate of change of speed of the bob at $\theta$= 30$^{\circ}$ is $(g=10 \, ms^{-1})$

When a ceiling fan is switched off, its angular velocity reduces to half its initial value after it completes 36 rotations. The number of rotations it will make further before coming to rest is (Assuming angular retardation to be uniform)

Two identical objects each of mass $50 \,kg$ are kept at a distance of separation of $50\, cm$ apart on a horizontal table. The net gravitational force at the mid-point of the line joining their centres is