Q1. A hollow conducting sphere of radius R is given a charge +Q. What is the work done in moving a charge q from the center of the sphere to a point at a distance R/3 from the center?
Correct Answer: Option A ((1 / 4πε₀) * (Qq / R))
Explanation: Detailed explanation will be updated shortly.
Q2. In a potentiometer experiment, the balancing length for a cell is found to be 240 cm. If the driver cell is replaced by another cell of half the EMF and the resistance of the primary circuit is halved, the new balancing length will be:
Correct Answer: Option A (240 cm)
Explanation: Detailed explanation will be updated shortly.
Q3. A square loop of side 'a' carrying current I₂ is placed at a distance 'a' from a long straight wire carrying current I₁. The net torque on the loop about the long straight wire as the axis is:
Correct Answer: Option A (0)
Explanation: Detailed explanation will be updated shortly.
Q4. A conducting rod of length L is rotating with a constant angular velocity ω about a point P located at a distance L/4 from one of its ends, in a uniform magnetic field B perpendicular to the plane of rotation. The induced EMF across the ends of the rod is:
Correct Answer: Option A ((1/2) BωL²)
Explanation: Detailed explanation will be updated shortly.
Q5. In a series LCR circuit, the voltage across the inductor and the capacitor are found to be equal at a particular frequency. The phase difference between the applied voltage and the circuit current is:
Correct Answer: Option A (π)
Explanation: Detailed explanation will be updated shortly.
Q6. A thin biconvex lens of focal length 'f' is cut vertically into two identical plano-convex halves. If a point object is placed at a distance of 2f from the original lens position on the principal axis, how many images will be formed by the separated halves?
Correct Answer: Option A (One image at 2f)
Explanation: Detailed explanation will be updated shortly.
Q7. In a Young's Double Slit Experiment, the 8th bright fringe is observed at a certain point on the screen when using light of wavelength λ in air. If the entire apparatus is immersed in a transparent liquid of refractive index μ = 1.6, what new order of bright fringe will be observed at the same point?
Correct Answer: Option A (5th)
Explanation: Detailed explanation will be updated shortly.
Q8. In a photoelectric effect experiment, when the frequency of incident radiation is increased from f to 2f, the stopping potential (Vₛ) changes from V₀ to V₁. Which of the following relations is correct? (Assume hf > φ, where φ is the work function)
Correct Answer: Option A (V₁ = 2V₀)
Explanation: Detailed explanation will be updated shortly.
Q9. In the given Zener diode voltage regulator circuit, the current through the Zener diode (I_z) is:
(Unregulated Input = 10V, R_s = 200Ω, Zener Voltage V_z = 6V, R_L = 400Ω)
Correct Answer: Option A (20 mA)
Explanation: Detailed explanation will be updated shortly.
Q10. From a uniform circular disc of radius R and mass M, a smaller circular disc of radius R/2 is removed such that its circumference touches the outer circumference of the original disc. The moment of inertia of the remaining portion about an axis perpendicular to the plane and passing through the center of the original disc is:
Correct Answer: Option A ((1/2) MR²)
Explanation: Detailed explanation will be updated shortly.
Q11. An electromagnetic wave propagates in the negative z-direction. The electric field vector E is along the positive x-direction. What is the direction of the magnetic field vector B?
Correct Answer: Option A (Positive y-direction)
Explanation: Detailed explanation will be updated shortly.
Q12. The binding energy per nucleon curve indicates that energy is released in both nuclear fission and fusion processes. This is because:
Correct Answer: Option A (Both processes result in the formation of more stable nuclei.)
Explanation: Detailed explanation will be updated shortly.
Q13. A satellite is in a stable circular orbit of radius R around the Earth. If it is given an instantaneous velocity boost in the direction of its motion, its subsequent path will be:
Correct Answer: Option A (A larger radius circular orbit)
Explanation: Detailed explanation will be updated shortly.
Q14. The B-H curves (hysteresis loops) for two magnetic materials A and B are shown. Which material is suitable for making the core of an electromagnet and a permanent magnet, respectively?
(Assume Loop A is tall and wide, Loop B is tall and narrow)
Correct Answer: Option A (Electromagnet: A, Permanent Magnet: B)
Explanation: Detailed explanation will be updated shortly.
Q15. An electron and a proton are accelerated from rest through the same potential difference V. The ratio of the de Broglie wavelength of the electron (λₑ) to that of the proton (λₚ) is approximately:
Correct Answer: Option A (1)
Explanation: Detailed explanation will be updated shortly.
Q16. The temperature of the junction of two insulating rods kept in series is T. The rods have lengths L₁ and L₂ and thermal conductivities K₁ and K₂. The ends are maintained at temperatures T₁ and T₂ (T₁ > T₂). The value of T is:
Correct Answer: Option A ((K₁T₁L₁ + K₂T₂L₂) / (K₁L₁ + K₂L₂))
Explanation: Detailed explanation will be updated shortly.
Q17. In the Bohr model for the hydrogen atom, the magnetic dipole moment of the electron in the nth orbit is proportional to:
Correct Answer: Option A (n⁻¹)
Explanation: Detailed explanation will be updated shortly.
Q18. A parallel plate capacitor is charged by a battery. The battery is then disconnected. If the distance between the plates is now doubled, the electrostatic energy stored in the capacitor:
Correct Answer: Option A (Is halved)
Explanation: Detailed explanation will be updated shortly.
Q19. A body performs Simple Harmonic Motion (SHM) with an amplitude A. What is the distance from the mean position where its kinetic energy is twice its potential energy?
Correct Answer: Option A (A / √2)
Explanation: Detailed explanation will be updated shortly.
Q20. In a transistor amplifier, the collector load resistance R_C is 4 kΩ. The input signal voltage is 20 mV and it produces a change of 30 µA in the base current and a change of 4 mA in the collector current. The voltage gain of the amplifier is:
Correct Answer: Option A (1000)
Explanation: Detailed explanation will be updated shortly.