1

### IIT-JEE 2007

This question contains STATEMENT-1 (Assertion) and STATEMENT-2 (Reason) and has 4 choices (a), (b), (c), (d) out of which ONLY ONE is correct.

STATEMENT-1 : Band gap in germanium is small. because
STATEMENT-2 : The energy gap of each germanium atomic energy level is infinitesimally small.
A
Statement - 1 is True, Statement - 2 is True; Statement - 2 is a correct explanation for Statement - 1
B
Statement - 1 is True, Statement - 2 is True; Statement - 2 is not a correct explanation for Statement - 1
C
Statement - 1 is True, Statement - 2 is False
D
Statement - 1 is False, Statement - 2 is True
2

### IIT-JEE 2006

According to Bohr's theory
En = Total energy, Kn = Kinetic Energy, Vn = Potential Energy, rn = Radius of nth orbit
Match the following

Column I

(A) Vn/Kn = ?
(B) If radius of nth orbit $\propto E_n^x,x = ?$
(C) Angular momentum in lowest orbital
(D) ${1 \over {{r_n}}} \propto {Z^y},y = ?$

Column II

(p) 0
(q) -1
(r) -2
(s) 1
A
(A) $\to$ r, (B) $\to$ p, (C) $\to$ q, (D) $\to$ s
B
(A) $\to$ r, (B) $\to$ q, (C) $\to$ p, (D) $\to$ s
C
(A) $\to$ s, (B) $\to$ p, (C) $\to$ q, (D) $\to$ r
D
(A) $\to$ p, (B) $\to$ r, (C) $\to$ q, (D) $\to$ s
3

### IIT-JEE 2005 Screening

The number of radial nodes of 3s and 2p orbitals are respectively
A
2, 0
B
0, 2
C
1, 2
D
2, 1
4

### IIT-JEE 2004 Screening

The radius of which of the following orbit is same as that of the first Bohr's orbit of hydrogen atom?
A
He+ (n = 2)
B
Li2+ (n = 2)
C
Li2+ (n = 3)
D
Be3+ (n = 2)