List of top Questions asked in KEAM- 2019

The Q factor for a damped oscillator is given by the
An object having a velocity 5 m/s is accelerated at the rate 2 m/s\textsuperscript{2 for 6 s. Find the distance travelled during the period of acceleration}
A boy formed a bubble and a liquid drop from the same soapy water. The pressure difference between inside and outside of the soap bubble is measured to be 100 N/m\(^2\). If the radius of the droplet is half of the radius of the bubble, then the pressure difference between the inside and outside of the droplet is:
Inside the engine of an automobile, the cylinder compresses the air from approximately standard temperature and pressure to one-twentieth of the original volume and a pressure of 50 atm. What is the temperature of the compressed air?
Some smoke is trapped in a small glass container and is viewed through a microscope. A number of very small smoke particles are seen in continuous random motion as a result of bombardment by air molecules. If the mass of the smoke particle is about \(10^{12}\) times higher than that of an air molecule, the average speed of a smoke particle is:
A Carnot engine is operating between a hot body and cold body maintained at temperatures \( T_1 \) and \( T_2 \) respectively. Consider the following three cases:
• Case-I: The temperature of the hot body is changed to \( T_1 + \Delta T \) and cold body is at \( T_2 \).
• Case-II: The temperature of the hot body is at \( T_1 \) and cold body is changed to \( T_2 + \Delta T \).
• Case-III: The temperature of the hot body is at \( T_1 \) and cold body is changed to \( T_2 - \Delta T \). The efficiency of the Carnot cycle is highest for:
In a water container, an aluminum piece of volume \( 0.5 \,\text{m}^3 \) is lowered through an external force, until it is completely submerged. In another identical water container, a lead piece of same volume was similarly submerged using the same amount of external force. The mass density of lead is 4 times larger than the mass density of the aluminum. If \( F_A \) and \( F_L \) are the buoyancy forces acting on aluminum and lead respectively, then which of the following statement is correct?
A spring of natural length \( l \) and spring constant 50 N/m is kept on a horizontal frictionless table with one end attached to a rigid support. First the spring was compressed by 10 cm and then released to hit a ball of mass 20 g kept at a distance \( l \) from the rigid support. If after hitting the ball, the natural length of the spring is restored, what is the speed with which the ball moved? (Ignore the air resistance)
The dimension of mutual inductance is (Denote dimension of current as A)
A pure inductor of inductance 0.1 H is connected to an AC source (of rms voltage) 220 V and angular frequency of 300 Hz. The rms current is
In an LCR series circuit (of inductance L, capacitance C and resistance R), the impedance is minimum when the angular frequency of the source is given by
Which of the following elements you need to remove to form an isotone family? (A) O-16
A magnetic field of $1$~T applied at an angle $\pi/3$ to the vertical direction is decreased to zero at a steady rate in one second. The magnitude of induced emf in a horizontally placed circular loop of radius $5$~cm is given by
Which of the following statements is not a property of nuclear force? (A) Attractive
For atoms, which of the following statement is correct? (A) Heavier nuclei have more neutrons
A brick of mass 2 kg slides down an incline of height 5 m and angle \( 30^\circ \). If \( \mu = \frac{1}{2\sqrt{3}} \), the velocity at the bottom is (Take \( g = 10 \text{ m/s}^2 \)) (A) 5 m/s
A hollow sphere and a solid sphere, of equal mass and equal radii roll down without slipping on an inclined plane. If the torques experienced are \( \tau_H \) and \( \tau_S \), then (A) \( \tau_H < \tau_S \)
The half-life of \( _{43}\text{Tc}^{99} \) is 6 hours. If 12 mg of \( _{43}\text{Tc}^{99} \) is injected to a patient, after 24 hours how much Tc will be left in the patient’s body? (A) 0 mg
Suppose two planets A and B revolve around a Sun in the galaxy. The semi-major axis of A and B are 1 and 5 AU (astronomical unit) respectively. If the period of revolution of A is 1 year, the period of revolution of B is (A) 1 year
A ball of mass 1 kg and radius 0.5 m, starting from rest rolls down on a $30^\circ$ inclined plane. The torque acting on the ball at the distance of 7 m from the starting point is close to (Take $g = 10 \text{ m/s}^2$) (A) 0.25 N-m
The radius of gyration about an axis through the center of a hollow sphere with external radius $a$ and internal radius $b$ is (A) \( \sqrt{\frac{2}{5}\frac{(a^{3}-b^{3})}{(a^{5}-b^{5})}} \)
If the radius of the earth suddenly decreases by half of its present value, the time duration of one day will be (A) 6 hours
A light emitting diode is (A) a n-p-n type semiconductor with a forward bias
For signal transmission, modulation is necessary
In the context of p-n junction, select the correct statement from the following: (A) The barrier potential remains constant under forward bias