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

The half-life of ⁴⁰K is 1.30 × 10⁹ y. A sample of 1.00 g of pure KCI gives 160 counts s⁻¹. Calculate the relative abundance of ⁴⁰K (fraction of ⁴⁰K present) in natural potassium.

Identify the logic gate represented by the circuit as shown and write its truth table.

Magnetic field lines can be entirely confined within the core of a toroid, but not within a straight solenoid. Why?

The following figure shows the input waveforms (A, B) and the output waveform (Y) of a gate. Identify the gate, write its truth table and draw its logic symbol.

What will be the values of input A and B for the Boolean expression `overline ((A +B) .(A*B)) =1?`

The output of an OR gate is connected to both the inputs of a NAND gate Draw the logic circuit of this combinaion of getes and write its truth table.

If the above capacitor is connected across a 6⋅0 V battery, find (a) the charge supplied by the battery, (b) the induced charge on the dielectric and (c) the net charge appearing on one of the coated surfaces.

An AND gate can be prepared by repetitive use of
(a) NOT gate
(b) OR gate
(c) NAND gate
(d) NOR gate.

Let  \[X = A \overline{ BC} + B\overline{ CA} + C\overline{AB } .\]   Evaluate X for A = 1, B = 0, C = 1. 

Let  \[X = A \overline{ BC} + B\overline{ CA} + C\overline{AB } .\]   Evaluate X for  A = B = C = 1. 

Let  \[X = A \overline{ BC} + B\overline{ CA} + C\overline{AB } .\]   Evaluate X for  A = B = C = 0.

Design a logical circuit using AND, OR and NOT gates to evaluate  \[A \overline { BC } + B \overline{ CA }\] .

Show that  \[AB + \overline {AB }\]  is always 1.

Why is the linear portion of the triode characteristic chosen to operate the triode as an amplifier?

The amplification factor of a triode operating in the linear region depends strongly on ____________ .

Derive an expression for voltage gain of the amplifier and hence show that the output voltage is in opposite phase with the input voltage.

How is linearly polarised light obtained by the process of scattering of light. Find the Brewster angle for air – glass interface, when the refractive index of glass = 1.5. 

Find the ratio of the potential differences that must be applied across the parallel and series combination of two capacitors C₁ and C₂ with their capacitances in the ratio 1 : 2 so that the energy stored in the two cases becomes the same.

An infinitely large thin plane sheet has a uniform surface charge density +σ. Obtain the expression for the amount of work done in bringing a point charge q from infinity to a point, distant r, in front of the charged plane sheet.