1 curie is

 

1.  1 dps

2.  3×10¹⁰ dps

3.  10⁶ dps s

4.  3.7×10¹⁰ dps

 

The following table 
 
is a truth table for

1. NAND gate

2. NOR gate

3. XOR gate

4. AND gate

1.  The substance completely disintegrates in 20 days
2.  The substance completely disintegrates in 40 days
3.  1/8 part of the mass of the substance will be left intact at the end of 40 days
4.  7/8 part of the mass of the substance disintegrates in 30 days

A source and an observer are moving towards each other with a speed equal to v/2, where v is the speed of sound. The source is emitting sound of frequency n. The frequency heard by one observer will be

1. zero

2. n

3. \(\frac{n}{3}\)

4. 3n