JEE Main Physics MCQs - Part 3
Questions 21-30 of 10021. A parallel plate capacitor with air between the plates has a capacitance of 8 pF. What will be the capacitance if the distance between the plates is reduced by half and the space between them is filled with a substance of dielectric constant 6?
22. Three resistors each of 4 Ω are connected to form a triangle. The resistance between any two terminals is:
23. The magnetic field at the center of a circular coil of radius R carrying current I is B. The magnetic field at a point on its axis at a distance R from the center is:
24. A cyclotron is used to accelerate:
25. A current loop of area 0.01 m² carries a current of 10 A. The magnetic dipole moment associated with the loop is:
26. If the number of turns in the primary and secondary coils is increased to two times each, the mutual inductance becomes:
27. A transformer has 500 turns in the primary and 1000 turns in the secondary. If the primary voltage is 200 V, the secondary voltage is:
28. Which of the following electromagnetic waves has the shortest wavelength?
29. An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. The image position is:
30. When light travels from air to glass (refractive index 1.5), its speed: