JEE Physics - MCQ Practice Questions

In pair production, a photon with energy 3 MeV converts near a nucleus into an electron-positron pair. The rest mass energy of electron/positron is 0.51 MeV. The excess energy appears as:

For a nucleus, the neutron-to-proton ratio (N/Z) increases with mass number. This is because:

In a MOSFET, the threshold voltage (Vth) increases when:

Impurity scattering dominates in semiconductors when:

A depletion mode MOSFET differs from enhancement mode in that:

The temperature coefficient of bandgap for silicon is approximately:

In a heterojunction like AlGaAs/GaAs, the main advantage is:

In a forward-biased p-n junction diode at room temperature, if the applied voltage is increased from 0.3V to 0.6V, by approximately what factor does the forward current increase? (assume kT/e ≈ 26mV)

The fill factor of a solar cell is defined as:

In an avalanche photodiode (APD), the internal gain (multiplication factor M) increases significantly due to:

The specific contact resistance of a metal-semiconductor junction is proportional to:

Which combination of semiconductor parameters would result in the highest intrinsic carrier concentration at 300K?

In a tunnel diode, negative differential resistance occurs because:

The current gain (β) of a BJT at constant IC depends on:

The noise figure of a semiconductor amplifier is lowest when operating at:

The Shockley ideal diode equation predicts that reverse saturation current (Is) is proportional to:

In a Zener diode, negative resistance occurs in the breakdown region because:

The Zener voltage of a heavily doped p-n junction is typically lower than that of a lightly doped junction because:

The Early voltage (V_A) of a BJT is inversely related to:

The subthreshold swing (SS) of a MOSFET is defined as the change in gate voltage required to change drain current by one decade. For an ideal MOSFET, SS at room temperature is approximately: