Universe — Physics STD 12 Science — Question

When a loop moves towards a stationary magnet with speed v, the induced emf in the loop is E. If the magnet also moves away from the loop with the same speed, then the emf induced in the loop is.

For small currents, ‘X’ obeys Ohm’s law. But when large currents are passed through the same conductor, it deviates from ohmic behaviour. Identify X.

Assertion  :  The air bubble shines in water.
Reason      : Air bubble in water shines due to refraction of light (a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

In which of the following ionic bond is present(a) NaCl(b) Ar(c) Si (d) Ge

Identify the paramagnetic substance(a) Iron(b) Aluminium(c) Nickel  (d) Hydrogen

Two ideal diodes are connected to a battery as shown in the circuit. The current supplied by the battery is

Which of the following products in a hydrogen atom are independent of the principal quantum number n? The symbols have their usual meanings.

In the formation of primary rainbow, the sunlight rays emerge at minimum deviation from rain-drop after(a) One internal reflection and one refraction(b) One internal reflection and two refractions(c) Two internal reflections and one refraction(d) Two internal reflections and two refractions