• P

• Q

• R

• S

• 200m

• 300m

• 360m

• 480m

• 
• 
• 

The foreign atom P is a

• monovalent atom

• divalent atom

• trivalent atom

• pentavalent atom

• 
• 
• 
• 

• the resistor R is disconnected

• the surrounding is bright

• the terminals of the battery are reversed

• the surrounding is dark

• 0 0

• 0 1

• 1 0

• 1 1

What should be done so that the bulb will light up?

• use a new bulb

• increases the number of dry cells

• reverse the connection of the diode

• connect a resistor in series with the bulb

• 100Hz, 2V

• 100Hz, 1V

• 50Hz, 2V

• 50Hz, 1V

• lnterchange R₁ and LDR

• Reverse the terminal of the battery

• Replace the npn transistor with a pnp transistor

• lnterchange R1 and R3