11. The materil used to coat inside the face of CRT is ______________?
A. Carbon
B. Sulphur
C. Silicon
D. Phosphorous
✅ The correct answer is option D.
Electronic instruments MCQs
12. The most accurate device for measuring voltage is ____________?
A. Voltmeter
B. Multimeter
C. CRO
D. VTVM
✅ The correct answer is option C.
13. A galvanometer of resistance G is shunted by a very small resistance S. The resistance of the resulting ammeter is ______________?
A. GS/(G+S)
B. G+S
C. G-S
D. None of the above
✅ The correct answer is option A.
14. A voltmeter is connected in a _____________ with the circuit component across which potential difference is to be measured?
A. Parallel
B. Series
C. Series or parallel
D. None of the above
✅ The correct answer is option A.
15. A galvanometer in series with a high resistance is called_______________?
A. An ammeter
B. A voltmeter
C. A wattmeter
D. None of the above
✅ The correct answer is option B.
16. If a multimeter has a sensitivity of 1000 O per volt and reads 50 V full scale, its internal resistance is _____________?
A. 20 kO
B. 50 kO
C. 10 kO
D. None of the above
✅ The correct answer is option B.
17. A VTVM has_____________input resistance than that of a multi meter?
A. More
B. Less
C. Same
D. None of the above
✅ The correct answer is option A.
18. Two multimeters A and B have sensitivities of 10 kO/V and 30 kO/V respectively. Then ______________?
A. Multimeter A is more sensitive
B. Multimeter B is more sensitive
C. Both are equally sensitive
D. None of the above
✅ The correct answer is option B.
19. A series ohmmeter circuit uses a 3 V battery and a 1 mA meter movement. What is the half-scale resistance for this movement ?
A. 3 kO
B. kO
C. kO
D. 6 kO
✅ The correct answer is option A.
20. A voltmeter should have ____________resistance?
A. Zero
B. Very high
C. Very low
D. None of the above
✅ The correct answer is option B.