List of top Questions asked in KEAM

For atoms, which of the following statement is correct? (A) Heavier nuclei have more neutrons

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 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

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

In the context of p-n junction, select the correct statement from the following: (A) The barrier potential remains constant under forward bias

For signal transmission, modulation is necessary

The Brewster's angle for air to water interface is

In a single slit diffraction (of width $\alpha$) by a monochromatic source of wavelength $\lambda$ the first minimum of the intensity distribution occurs at an angle

A monochromatic source of wavelength 600 nm was used in Young's double slit experiment to produce interference pattern. $I_1$ is the intensity of light at a point on the screen where the path difference is 150 nm. The intensity of light at a point where the path difference is 200 nm is given by

A TV transmitting antenna is 81 m tall. It has a half-power beam width of 10 degrees. If the receiving antenna is at the ground level, the service area covered by the transmitter is determined by

In the amplitude modulation mode of transmission, the normal speech signal is with a maximum frequency of 5 kHz. If the carrier frequency is 200 kHz, the modulated signal will have the frequencies varying between

An object is placed at 9 cm in front of a concave mirror of radius of curvature 12 cm. The following statement is true:

A parallel plate capacitor (of capacitance \( C \)) with circular plates of radius \( r_0 \) located at positions \( \pm \alpha \), is connected in series with a resistor \( R \) and is charged by a battery of voltage \( V \). Consider a circular loop \( L \) of radius \( \frac{r_0}{2} \) parallel to the capacitor plates is located at the center. Which of the following statements is correct?

An optician prescribes a lens of power +2.5 D. The focal length of the lens in water is (Indices: Lens = 1.5, Water = 1.33):

A monochromatic light of frequency \( \nu = \frac{1}{6.63} \times 10^{16} \) Hz is produced by a laser. The power emitted is \( P = 10^{-2} \) W. The average number of photons per second emitted by the source is

The work function of three photosensitive materials are: Sodium (2.75 eV), copper (4.65 eV) and gold (5.1 eV). Which of the following statements is correct (Visible light range: $4 \times 10^{14}$ Hz to $8 \times 10^{14}$ Hz)?

The radiation produced by a 100 W bulb has the following property

The electric field of an electromagnetic wave in free space is given by \( \vec{E} = 5\sin\left(\tfrac{2\pi}{3}z - \omega t\right)\hat{y} \) V/m. Which of the following statements is correct?

The variation of speed (in m/s) of an object with time (in seconds) is given by the expression $V(t) = V_0 - 5t + 5t^2$

A boat is moving from the east bank to the west bank on a south flowing river. If the speed of the boat is 4 km/h and that of the river is 3 km/h. If the width of the river is 2 km, the distance travelled by the boat is