$\mathrm{In} \mathrm{the} \mathrm{given} \mathrm{circuit} \mathrm{power}$
$\mathrm{developed} \mathrm{in} 1\mathrm{k\Omega } \mathrm{resistor} \mathrm{is}$

1.  36 mW

2.  12 mW

3.  144 mW

4.  64 mW

The given circuit has two ideal diodes connected as shown in the figure below. The current flowing through the resistance $R_1$ will be

(1) 2.5 A                     

(2) 10.0 A

(3) 1.43 A                   

(4) 3. 13 A

The given graph represents the V-I characteristic for a semiconductor device. Which of the following statement is correct?

A Zener diode, having breakdown voltage equal to 15 V, is used in a voltage regulator circuit, as shown in the figure. The current through the diode is:

1. 10 mA

2. 15 mA

3. 20 mA

4. 5 mA

A p-n photodiode is fabricated from a semiconductor with a band gap of $2.5 \mathrm{eV}.$ It can detect a signal of wavelength 

(1) $6000 \stackrel{\circ }{\mathrm{A}}$                                   
(2) $4000 \mathrm{nm}$
(3) $6000 \mathrm{nm}$                                 
(4) $4000 \stackrel{\circ }{\mathrm{A}}$