NEET 2016 Phase 1 · PhysicsPrevious Year Question
An astronomical telescope has objective and eyepiece of focal lengths 40 cm and 4 cm respectively. To view an object 200 cm away from the objective, the lenses must be separated by a distance
Answer: (D) 54.0 cm. Answer: (D) 54.0 cm Solution: The object is at a finite distance, so first find the image formed by the objective.
- A.37.3 cm
- B.46.0 cm
- C.50.0 cm
- D.54.0 cm✓
Correct Answer
(D) 54.0 cm
Solution & Explanation
Answer: (D) 54.0 cm Solution: The object is at a finite distance, so first find the image formed by the objective. Objective: f₀ = 40 cm, u = −200 cm. 1/v − 1/u = 1/f₀ 1/v = 1/40 + 1/(−200) = 5/200 − 1/200 = 4/200 = 1/50 v = 50 cm (real image, 50 cm behind the objective). For relaxed viewing this image lies at the focus of the eyepiece, so the eyepiece is placed a further f_e = 4 cm beyond it. Separation = v + f_e = 50 + 4 = 54.0 cm.
🎯
43,000+ questions in हिंदी & English · one-tap toggle
Open →📚Practice all NEET Physics PYQs chapter-wise →💡Don't get it? Learn the Ray Optics And Optical Instruments concepts →Practice NEET 2016 Phase 1 Physics — free, with instant solutions
43,000+ NEET questions solved step-by-step, chapter-wise, in the MedicNEET app.
More NEET PYQ solutions
PhysAn electric dipole with dipole moment 5 × 10⁻⁶ C·m is aligned with the direction of a uniform electric field of magnitude 4 × 10⁵ N/C. The dipole is then rotated through an angle of 60° with respect to the electric field. The change in the potential energy of the dipole is:PhysThe plates of a parallel plate capacitor are separated by d. Two slabs of different dielectric constant K1 and K2 with thickness 3d/8 and d/2 respectively are inserted in the capacitor. Due to this, the capacitance becomes two times larger than when there is nothing between the plates. If K1/K2 = 1.25, the value of K1 is:PhysA ball of mass 0.5 kg is dropped from a height of 40 m. It hits the ground and rebounds to a height of 10 m. The impulse imparted to the ball during its collision with the ground is (g = 9.8 m/s²):PhysA 2 A current is flowing through two different small circular copper coils having radii ratio 1 : 2. The ratio of their respective magnetic moments will bePhysAn electron (mass 9 × 10⁻³¹ kg and charge 1.6 × 10⁻¹⁹ C) moving with speed c/100 (c = speed of light) is injected into a magnetic field B of magnitude 9 × 10⁻⁴ T perpendicular to its direction of motion. We wish to apply a uniform electric field E together with the magnetic field so that the electron does not deflect from its path. Then (speed of light c = 3 × 10⁸ m s⁻¹)PhysA container has two chambers of volumes V₁ = 2 litres and V₂ = 3 litres separated by a partition made of a thermal insulator. The chambers contain n₁ = 5 and n₂ = 4 moles of ideal gas at pressures p₁ = 1 atm and p₂ = 2 atm, respectively. When the partition is removed, the mixture attains an equilibrium pressure of:PhysTwo gases A and B are filled at the same pressure in separate cylinders with movable pistons of radius r_A and r_B, respectively. On supplying an equal amount of heat to both systems reversibly under constant pressure, the pistons of gas A and gas B are displaced by 16 cm and 9 cm, respectively. If the change in their internal energy is the same, then the ratio r_A/r_B is equal to:PhysAn oxygen cylinder of volume 30 litre has 18.20 moles of oxygen. After some oxygen is withdrawn from the cylinder, its pressure drops to 11 atmospheric pressure at temperature 27 °C. The mass of the oxygen withdrawn from the cylinder is nearly equal to: [Given R = 100/12 J mol⁻¹ K⁻¹, molecular mass of O₂ = 32, 1 atm = 1.01 × 10⁵ N m⁻²]