Physics Ncert Solutions Class 12th

The spectrum of a black body at two temperature 127°C and 527°C is shown in the figure. Let A1 and A2 be the areas under the two curves respectively. The value A_1/A_{2 is:}

For the transistor circuit as shown. If b = 100, voltage drop between emitter and base is 0.7 V then value of VCE will be:-

The logic gate realised from the circuit as shown in figure is (P and Q are inputs and Z is output)

Avalanche breakdown of p-n junction diode is due to

What is the current through an ideal P – N junction diode shown in figure below?

In a transistor if $\frac{I_C}{E_E}=\alpha$ and $\frac{I_C}{I_B}=\beta$ . If $\alpha$ varies between $\frac{20}{21}$ and $\frac{100}{101}$ , then the value of $\beta$ lies between

Statement A: In intrinsic semiconductors, conductivity is mainly due to the breakage of covalent bonds.

Statement B: In extrinsic semiconductors, the conductivity is mainly due to the addition of impurities.

An AND gate can be prepared by repetitive use of

a) NOT gate (b) OR gate            (c) NAND gate                 (d) NOR gate

A thermodynamic system is taken through the cycle ABCD as shown in figure. Heat rejected by the gas during the cycle is

In a series $C-R$ circuit shown in figure, the applied voltage is $10V$ and the voltage across the capacitor is found to be . The voltage across $R$ and the phase difference between current and the applied voltage will be respectively.