Question

Match the Columns I and II.

Column I		Column II
A	Field emission	1	Heat is supplied to the metal surface
B	Photoelectric emission	2	Electric field is applied to the metal surface
C	Thermionic emission	3	Light of suitable frequency illuminates the metal surface
D	Secondary emission	4	Striking fast moving electrons on the metal surface

• A. $(A) \rightarrow(2) ; (B) \rightarrow(3) ; C \rightarrow(1) ; (D) \rightarrow (4)$
• B. $(A) \rightarrow (1); (B) \rightarrow (3); C \rightarrow (2); (D) \rightarrow (4)$
• C. $(A) \rightarrow (4); (B) \rightarrow (1); C \rightarrow (3); (D) \rightarrow (2)$
• D. $( A ) \rightarrow(4) ;( B ) \rightarrow(3) ; C \rightarrow(2) ;(D) \rightarrow(1)$

Answer 1

Answer: (A)

$(A) \rightarrow(2) ; (B) \rightarrow(3) ; C \rightarrow(1) ; (D) \rightarrow (4)$