Practice MCQ Questions and answers on Physics-GK

91

Quality of transmission depends upon

A) Nature of signal only B) Nature of medium only C) Both (A) and (B) D) Neither A nor B

Discuss

Answer & Solution

Answer: Option C

Solution:

Quality of transmission is governed both by nature of signal and nature of communication channel/medium.

92

Circuit breaker usually operate under

A) After D. C. component has ceased B) Transient state of short-circuit current C) Sub-transient state of short-circuit current D) Steady state of short-circuit current

Discuss

Answer & Solution

Answer: Option B

Solution:

Circuit breaker usually operate under transient state of short-circuit current.

93

The resistance of the human body (dry condition) is of the order of

A) 10¹ Ohm B) 10² Ohm C) 10³ Ohm D) None of these

Discuss

Answer & Solution

Answer: Option D

Solution:

According to National Institute of occupational safety and health, Under dry condition, the resistance of the human body is 100,000 ohms. Under wet condition, the resistance is reduced to 1000 ohms.

94

Which component of an IED creates an electrical charge?

A) Activator B) Fuse C) Explosive D) Power source

Discuss

Answer & Solution

Answer: Option D

Solution:

The power source such as a Battery of an IED creates an electrical charge. An Improvised Explosive Device (IED) is a bomb constructed and deployed in ways other than in conventional military action.

95

A multimeter is used to measure

A) Current B) Voltage C) Resistance D) All of the above

Discuss

Answer & Solution

Answer: Option D

Solution:

A digital multimeter is a test tool used to measure two or more electrical values—principally voltage (volts), current (amps) and resistance (ohms).

96

Which of the following was the first theory of superconductivity?

A) Ginzburg Landau theory B) London theory C) Resonating valence bond theory D) Quantum field theory

Discuss

Answer & Solution

Answer: Option B

Solution:

London theory was the first theory of superconductivity.

97

A wire of copper having length I and area of cross-section A is taken and a current i is flown through it. The power dissipated in the wire is P. If we take an aluminium wire having same dimensions and pass the same current through it, the power dissipated will be

A) P B) < P C) > P D) 2P

Discuss

Answer & Solution

Answer: Option C

Solution:

Aluminum has a resistivity varying from 2.65 to 2.82 × 10−8 Ω m. The resistivity of copper is generally given as: 1.72 x 10-8 Ω.m. So, since resistivity of aluminium is higher than that of copper, so power dissipated will be greater than P. this is because rest of the factors (l, A and i) are constant.

98

A wire carrying current is

A) Positively charged B) Negatively charged C) Neutral D) Charged with a type depending upon current strength

Discuss

Answer & Solution

Answer: Option C

Solution:

A wire carrying current is neutral.

99

Carbon Arc lamps are commonly used in

A) Cinema projectors B) Photography C) Vehicles D) Domestic lighting

Discuss

Answer & Solution

Answer: Option A

Solution:

Carbon Arc lamps are commonly used in cinema projectors.

100

Low voltage cables are meant for use up to

A) 3.3 kV B) 1.1 kV C) 11 kV D) 0.5 kV

Discuss

Answer & Solution

Answer: Option B

Solution:

Low Voltage Cables are used to supply power for use up to 1.1 kV.