PUC Science 2nd PUC Class 12 - Karnataka Board PUC Question Bank Solutions

A paramagnetic material is placed in a magnetic field. Consider the following statements:-
(A) If the magnetic field is increased, the magnetisation is increased.
(B) If the temperature is increased, the magnetisation is increased.

A paramagnetic material is kept in a magnetic field. The field is increased till the magnetisation becomes constant. If the temperature is now decreased, the magnetisation ___________ .

A ferromagnetic material is placed in an external magnetic field. The magnetic domains ______________ .

The magnetic susceptibility is negative for _____________ .

The permanent magnetic moment of the atoms of a material is not zero. The material ________________ .

The permanent magnetic moment of the atoms of a material is zero. The material _________________ .

When a ferromagnetic material goes through a hysteresis loop, the magnetic susceptibility
(a) has a fixed value
(b) may be zero
(c) may be infinity
(d) may be negative

A rod is inserted as the core in the current-carrying solenoid of the previous problem. (a) What is the magnetic intensity H at the centre? (b) If the magnetization I of the core is found to be 0.12 A m⁻¹, find the susceptibility of the material of the rod. (c) Is the material paramagnetic, diamagnetic or ferromagnetic?

Write the functions of the three segments of a transistor.

The figure shows the input waveforms A and B for ‘AND’ gate. Draw the output waveform and write the truth table for this logic gate.

The potential difference between the terminals of a 6.0 V battery is 7.2 V when it is being charged by a current of 2.0 A. What is the internal resistance of the battery?

The energy density in the electric field created by a point charge falls off with the distance from the point charge as

A capacitor of capacitance 500 μF is connected to a battery through a 10 kΩ resistor. The charge stored in the capacitor in the first 5 s is larger than the charge stored in the next.

(a) 5 s

(b) 50 s

(c) 500 s

(d) 500 s

A capacitor C₁ of capacitance 1 μF and a capacitor C₂ of capacitance 2 μF are separately charged by a common battery for a long time. The two capacitors are then separately discharged through equal resistors. Both the discharge circuits are connected at t = 0.

(a) The current in each of the two discharging circuits is zero at t = 0.

(b) The currents in  the two discharging circuits at t = 0 are equal but not zero.

(c) The currents in the two discharging circuits at t = 0 are unequal.

(d) C₁ loses 50% of its initial charge sooner than C₂ loses 50% of its initial charge.

Find the charge on the capacitor shown in the figure.

(a) Find the current in the 20 Ω resistor shown in the figure. (b) If a capacitor of capacitance 4 μF is joined between the points A and B, what would be the electrostatic energy stored in it in steady state?

A capacitance C, a resistance R and an emf ε are connected in series at t = 0. What is the maximum value of (a) the potential difference across the resistor (b) the current in the circuit (c) the potential difference across the capacitor (d) the energy stored in the capacitor (e) the power delivered by the battery and (f) the power converted into heat?

A 20 μF capacitor is joined to a battery of emf 6.0 V through a resistance of 100 Ω. Find the charge on the capacitor 2.0 ms after the connections are made.

The plates of a capacitor of capacitance 10 μF, charged to 60 μC, are joined together by a wire of resistance 10 Ω at t = 0. Find the charge on the capacitor in the circuit at (a) t = 0 (b) t = 30 μs (c) t = 120 μs and (d) t = 1.0 ms.