Multiple Choice
For listening radio in cars, external radio aerials are used because
A) radio waves have shorter wavelength
B) radio waves have longer wavelength
C) radio waves cannot pass through window
D) radio waves require a medium to propagate
Correct Answer:
Verified
Correct Answer:
Verified
Q15: Resistance of metal is affected by<br>A)presence of
Q16: Constructive interference happens when two waves are<br>A)out
Q17: At constant temperature, resistance and cross-sectional area
Q18: At threshold voltage, resistance of diode<br>A)decreases<br>B)increases<br>C)remains constant<br>D)varies
Q19: Effect of diffraction is greatest if waves
Q20: A rectifier converts<br>A)DC to AC<br>B)AC to DC<br>C)voltage
Q22: For destructive interference, the path difference is<br>A)odd
Q23: In NTC thermistor on increasing temperature, the
Q24: If the connections across the resistor are
Q25: Threshold voltage at which LED emits light