One good thing to remember while preparing for UGC NET is Comparison Of Various Logic Families and Microwave Frequency band.

Ans C

now int, char and double are basically datatypes in C language.lets understand what each of them mean

A] Int is used to define integers.

int i;

i = 5;

here i is defined as integer (basically it is a memory location allocated to store integer value) and assigned a value 5.

  

B] char is used to define character.

char let ; 

let = 'x';

C] double use to define floating point numbers (e.g = 5.46  , 6.81)

double j  ;

j = 4.5;

Now consider above question we have,

  int i = 3;

  int j = 7;

  double  f = 5.5 ;

double g = 4.5;

char ch = 'T' ;

• ||  means OR  
• && means AND   
• == means Equal to

Consider option A

 (i < = 5 ) && ( ch == 'T')

for above eq. to give true value both expression should be true lets check them.

as i =3  it is less than 5 so first expression is indeed true.

now ch = 'T' is also given in question so it is also true as both expressions are true above equation will give vale  TRUE.

Consider option B

(i < 8 )  || ( ch = ' L')

for above eq. to give true value one expression should be atleast true lets check them.

as i =3  it is less than 8 so first expression is indeed true.

so above equation gives TRUE value.

Consider option C

(f > 6)  || (i*j < 15)

as f = 5.5 first expression is false

i* j = 16.5  which is greater than 15 so this expression is also false.

so the value of equation is FALSE

So option C is correct option.

Ans . B

A]  Current density (J ) is given by

J = p* Vd          ----------------------- (1)

where,
p = charge density
Vd = drift velocity


B] Charge density is basically no. of charges present inside the material so it is given by.
p = n* q ---------------------------------(2)

where,
n = no. of charge carrier (say electron in our case)
           q = charge carried by charge carrier.

C] Drift Velocity is given by
Vd = u*E  -------------------------------(3)
where,
u = Mobility
E =  Electric field.

So J becomes,
J = n*q*u*E  -------------------(4)

D] Ohm's law according to classical electromagnetic theory is given by,
J = k*E -------------------------------(5)
where,
k = conductivity
E = Electric field.

 Equating 4 and 5 we have

k = n* q* u

for above question
  n = Nd as it is n-type semiconductor.
q = charge on electron = 1.6E-16
u = 1350
 substituting in equation (6) we get,

k = 9.2592 E+14
so answer is B