Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions for Physics

Answer the following question :

Distinguish between digital and analogue signals.

A triangular loop of wire placed at abc is moved completely inside a magnetic field which is directed normal to the plane of the loop away from the reader to a new position a'b'c'. What is the direction of the current induced in the loop? Give reason.

In the given circuit diagram a voltmeter ‘V’ is connected across a lamp ‘L’. Ho would (i) the brightness of the lamp and (ii) voltmeter reading ‘V’ be affected, if the value of resistance ‘R’ is decreased? Justify your answer.

A 10 V battery of negligible internal resistance is connected across a 200 V battery and a resistance of 38Ω as shown in the figure. Find the value of the current in circuit.

A 5 V battery of negligible internal resistance is connected across a 200 V battery and a resistance of 39Ω as shown in the figure. Find the value of the current in circuit.

You are given a circuit below. Write its truth table. Hence, identify the logic operation carried out by this circuit. Draw the logic symbol of the gate it corresponds to.

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?